NHGIS News

Updated Land Cover Summaries for Census Tracts, County Subdivisions, Counties, and Places

November 11, 2024

NHGIS has released updated land cover summaries for 2010, 2020, and 2022-vintage census tracts, county subdivisions, counties, and places.

The land cover data come from the National Land Cover Database (NLCD), which is derived from 30-meter resolution Landsat imagery. The NLCD summaries identify the proportion of area covered by each of 16 land cover classes in 2001, 2004, 2006, 2008, 2011, 2013, 2016, 2019, and 2021.

This release expands our prior release of land cover summaries to include more geographic levels and more years of NLCD data.

These land cover summaries were created by IPUMS NHGIS Diversity Fellows, Prayash Pathak Chalise and Saemi Lee, during Summer 2024. Support for the Diversity Fellows comes from National Science Foundation (NSF) Grant SES2316650.

For more information on these updates, see the Revision History. For complete documentation and to download the files, see the Environmental Summaries page.

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Several Crosswalk Updates Including New Tract-to-Tract Crosswalks

June 25, 2024

A new release of NHGIS geographic crosswalks includes a wide range of updates, including:

• New crosswalks from tracts to tracts and from blocks to larger areas, enabling more flexible linkages of 1990-2022 data using consistent geography
• Extended 2000 crosswalks to include Puerto Rico
• A broader set of interpolation weights including separate weights for owner- and renter-occupied units
• Standardized naming, formats, and documentation for all crosswalks

For more information on these updates, see the Revision History. For complete documentation and to download the files, see the Geographic Crosswalks page.

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Webinar on Accessing NHGIS in R

March 19, 2024

In a webinar given on March 5, 2024, IPUMS staff member Finn Roberts demonstrates how to use the ipumsr package in R to explore NHGIS metadata and request and load NHGIS data. Finn walks through an example application, discusses some of the key benefits of accessing NHGIS within the R environment, and answers many questions from those who attended.

We have now posted the video, the slides, and a transcript of the Q&A.

For a brief primer on what ipumsr has to offer for NHGIS users, see our blog post from September 2023.

For a listing of all available NHGIS webinars, see the User Guide page.

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1980 Block Boundaries for 55 More Metros (v4.0)

February 27, 2024

NHGIS has released its fourth set of GIS boundary files for 1980 census blocks. This release adds 47 metropolitan areas including St. Louis, Pittsburgh, Nassau-Suffolk, Tampa-St. Petersburg, and Fort Lauderdale and completes 8 metro areas with partial coverage in Version 3.0 to provide full coverage of New England. In total, we now provide block boundaries for all or part of 148 metro areas across 46 states, including the top 20 largest metro areas by 1980 population and 42 of the 50 largest.

Click below for a list of the newly added metro areas:

Both the statewide and nationwide shapefiles have been updated to include the new metropolitan areas. These files are provided through the 1980 Block Boundaries page along with complete documentation and block-level summary statistics.

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2022 ACS 5-Year Summary File, Time Series Extensions & GIS Boundary Files

December 14, 2023

In a single release, NHGIS has extended each of its three main data types: source summary tables, time series tables, and GIS boundary files.

First, NHGIS has added the 2018-2022 5-Year Summary File from the American Community Survey (ACS). Over 1,100 new tables are now available for geographic areas as small as block groups.

Second, NHGIS has extended 115 time series tables to include 2018-2022 ACS 5-year data. These time series tables now cover 13 5-year periods from 2006-2010 through 2018-2022 in addition to decennial census years.

Third, NHGIS has added 79 new GIS boundary files based on 2022 TIGER/Line Shapefiles. The new files correspond to the geographic units identified in 2022 American Community Survey data. The release includes nationwide files for 27 geographic levels and 52 state-specific files for block groups.

For more information about this release, see the Revision History.

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2022 ACS 1-Year Summary File now available

November 30, 2023

NHGIS has added the 2022 1-Year Summary File from the American Community Survey (ACS). Over 1,400 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2022 GIS boundary files soon. Until then, users may use the 2021 boundary files with 2022 tables for most geographic levels and areas.

Note: Beginning with this release, for county-level tables, the Census Bureau now identifies planning regions in Connecticut in place of Connecticut's historical counties, which have long had no official administrative function. The Census Bureau provides crosswalks and relationship files that describe the planning regions' associations with other areas identified in earlier data releases.

For more information about this release, see the NHGIS Revision History and the ACS table documentation.

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Blog post: Accessing NHGIS in R

September 19, 2023

R users have a powerful new way to access IPUMS NHGIS!

The July 2023 release of ipumsr 0.6.0 includes a fully-featured set of client tools enabling R users to get NHGIS data and metadata via the IPUMS API. Without leaving their R environment, users can find, request, download and read in U.S. census summary tables, geographic time series, and GIS mapping files for years from 1790 through the present.

NHGIS staffers Finn Roberts & Jonathan Schroeder have written a new IPUMS blog post that gives an overview of the possibilities and describes how to get started.

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2020 Census Demographic & Housing Characteristics File (DHC)

September 5, 2023

NHGIS has released all data from the 2020 Census Demographic and Housing Characteristics File (DHC). There are 249 tables providing summary data on age, sex, race & ethnicity, urban/rural status, household size and relationship, cohabiting and same-sex couples, housing tenure, and group quarters types.

The tables are available for 164 geographic levels down to census blocks.

NHGIS separates the 2020 DHC into three datasets, each providing tables for a different set of geographic levels:

• 2020_DHCa: DHC - P & H Tables [Blocks & Larger Areas] – 141 tables
• 2020_DHCb: DHC - PCT & HCT Tables [Tracts & Larger Areas] – 98 tables
• 2020_DHCc: DHC - PCO Tables (Group Quarters Population Only) [Counties & Larger Areas] – 10 tables

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GIS Boundary Files for 2020 Urban Areas & PUMAs

September 5, 2023

NHGIS has released two new GIS boundary files representing 2020 Public Use Microdata Areas (PUMAs) and 2020 urban areas. The new files are based on additions the Census Bureau made to their 2020 TIGER/Line Shapefiles after the original release of those files.

The new boundary files take the place of two files that NHGIS had already released with labels indicating that they were "2020" PUMAs and urban areas. In fact, those files represented 2010 PUMAs and urban areas, which are the versions identified in the American Community Survey 2016-2020 5-year summary tables. We have renamed those two files in NHGIS to indicate that they represent 2010 PUMAs and urban areas with a 2020 TIGER/Line+ basis.

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Time Series Updates: All ACS 5-Year Periods 2006-2021 & Ability to Select Years

May 2, 2023

This release extends our collection of time series tables to include American Community Survey (ACS) data for all 5-year periods from 2006-2010 through 2017-2021. Previously, the tables included 5-year data mainly only for two periods, 2008-2012 and 2015-2019.

We have also added new functionality that enables users to request specific years for time series tables in the NHGIS Data Finder. Previously, NHGIS data files would include all available years for any requested time series tables. The ability to select years allows users to reduce file size by limiting requests to only years of interest.

The new extensions apply only to nominally integrated tables, not geographically standardized tables. In total, 116 tables are involved:

• 75 tables had included only two ACS 5-year periods (2008-2012 and 2015-2019) and now include 12 5-year periods, along with multiple census years
• 35 tables had included only decennial census data but now also include ACS data for 12 5-year periods
  • These all cover "short-form subjects" such as age, race, household size, and tenure
• 5 tables are new:
  • 2 tables provide median age down to the tract level. (The previously available median age tables go down to the county level.)
  • 3 tables use the most detailed categories available in ACS tables for sex by age, foreign place of birth, and housing vacancy
• 1 table for persons born in Yugoslavia had included data for 2007-2011, the last period for which the ACS identified this category, and now also includes 2006-2010

For a complete listing of new and extended tables, see the Revision History.

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Annual Census Tract Population Estimates, 2000-2019

April 24, 2023

To bridge the gap between the once-a-decade census of population and the 5-year American Community Survey estimates, NHGIS has generated annual census tract population estimates, broken down by age, sex and race. Our annual estimates are available from 2000-2019, and we use 2010-vintage census tracts as our reporting units. For each year-census tract pair, we provide population estimates for all unique combinations of age (18 categories), sex (two categories), and race (six categories).

Our annual estimates use data from the 2000 and 2010 Decennial Censuses, including both Summary File 1 and the Modified Race Summary File (MRSF), the US Census Bureau's Population Estimates Program, and NHGIS 2000-2010 census block geographic crosswalks.

For more information, and to download the files, see the Annual Tract Estimates page.

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Privacy-Protected 2010 Census Demonstration Data from the 2023-04-03 DHC Demonstration Data Product

April 3, 2023

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run (2023-04-03 vintage) of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from their new system, the Census Bureau plans to release a series of demonstration data products. The recently released DHC Demonstration product was generated by the Census Bureau's most up-to-date version of their disclosure avoidance system and includes data on sex, age, race, Hispanic ethnicity, population in households, groups quarters, and housing units. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each demonstration data product. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of persons identifying as Hispanic).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The release of this new data product is based on the 2023-04-03 vintage of the DHC Demonstration Data. The 2023-04-03 vintage was created using the same production parameters as will be used to create the 2020 Demographic and Housing Characteristics File.

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1980 Block Boundaries for 41 More Metros (v3.0)

March 14, 2023

NHGIS has released its third set of GIS boundary files for 1980 census blocks. This release adds 41 metropolitan areas including Detroit, Washington D.C., Dallas, Houston, and Boston. In total, we now provide block boundaries for all or part of 103 metro areas across 45 states, including the top 10 largest metro areas by 1980 population and 24 of the 30 largest.

Click below for a list of the newly added metro areas:

Both the statewide and nationwide shapefiles have been updated to include the new metropolitan areas. These files are provided through the 1980 Block Boundaries page along with complete documentation and block-level summary statistics.

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2021 GIS boundary files

December 21, 2021

NHGIS has released 85 new GIS boundary files based on 2021 TIGER/Line Shapefiles. The new files correspond to the geographic units identified in 2021 American Community Survey data. The release includes nationwide files for 33 geographic levels and 52 state-specific files for block groups.

The GIS Files documentation page provides more information, including an overview of how NHGIS boundary files differ from the Census TIGER/Line data.

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2017-2021 ACS 5-Year Summary File Now Available

December 13, 2022

NHGIS has added the 2017-2021 5-Year Summary File from the American Community Survey (ACS). Over 1,100 new tables are now available for geographic areas as small as block groups.

We expect to release 2021 GIS boundary files that correspond to the the 2021 1-year and 5-year ACS data tables very soon. In the meantime, for most areas and for most geographic levels, it is possible to map and analyze 2021 ACS data by joining the data with the 2020 boundary files.

For more information about this release, see the Revision History.

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New & Revised Context Fields for Data Tables

October 28, 2022

A new release of NHGIS metadata and data includes wide-ranging updates to the "context fields" in NHGIS data files for summary tables. This adds many useful fields for our older datasets, including some area measures, geographic coordinates, identifiers for encompassing geographic units, data suppression flags, and geographic class codes (e.g., incorporated vs. unincorporated places).

Previously, NHGIS had omitted many of the context fields that were available in our source files because the original NHGIS data structure allowed context fields mainly only for specific geographic identifiers (those that were needed to identify units for one of the geographic levels covered in the dataset). After a series of recent updates to our system, we are now able to include most types of context fields. We have completed a broad review of available context fields and identified many to add as well as some to drop or revise.

Across all NHGIS datasets, the update includes 1,428 revisions: 1,145 added fields, 60 dropped fields (which were altogether empty in our source files), and 223 fields with a revised code or description. We detail all updates in an Excel spreadsheet (link below), which lists codes and descriptions for the affected fields both before and after the update (where "<na>" indicates that the field either was not or is no longer available).

• Updates to NHGIS Context Fields, October 28, 2022

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2021 ACS 1-Year Summary File now available

October 28, 2022

NHGIS has added the 2021 1-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2021 GIS boundary files soon. Until then, users may use the 2020 boundary files with 2021 tables for most geographic levels and areas.

For more information about this release, see the NHGIS Revision History and the ACS table documentation.

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Privacy-Protected 2010 Census Demonstration Data from the 2022-08-25 DHC Demonstration Data Product

August 31, 2022

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run (2022-08-25 vintage) of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from their new system, the Census Bureau plans to release a series of demonstration data products. The recently released DHC Demonstration product was generated by the Census Bureau's most up-to-date version of their disclosure avoidance system and includes data on sex, age, race, Hispanic ethnicity, population in households, groups quarters, and housing units. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each demonstration data product. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of persons identifying as Hispanic).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The release of this new data product is based on the 2022-08-25 vintage of the DHC Demonstration Data.

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1980 Block Boundaries for 14 More Metros: NYC, LA, Baltimore, Atlanta…

August 19, 2022

NHGIS has released its second set of GIS boundary files for 1980 census blocks. This release adds 14 metropolitan areas including New York City, Los Angeles, Baltimore, Atlanta, Memphis, and Nashville. In total, we now provide block boundaries for 62 metro areas across 37 states, including 5 of the 6 largest metro areas by 1980 population.

Click below for a list of the newly added metro areas:

 

The statewide and nationwide shapefiles have been updated to include the new metropolitan areas. These files are provided through the 1980 Block Boundaries page along with complete documentation and block-level summary statistics.

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2016-2020 ACS 5-Year Summary File now available

April 26, 2022

NHGIS has added the 2016-2020 5-Year Summary File from the American Community Survey (ACS). Over 1,100 new tables are now available for geographic areas as small as block groups.

This is the first release of ACS 5-year summary data to use new 2020 census geographies, including many changes in definitions for census tracts and block groups. NHGIS has added geographic crosswalks between the older and newer definitions to support comparisons between the new estimates and data from earlier ACS releases within tracts and block groups.

For more information about this release, see the Revision History.

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Geographic Crosswalks for 2010-2020 ACS Data

April 1, 2022

To support comparisons between new 2020 American Community Survey (ACS) 5-year summary tables and ACS data from earlier years, NHGIS has extended its collection of geographic crosswalks to include crosswalks from 2010 block groups to 2020 block groups, census tracts, and counties, and from 2020 block groups to 2010 block groups, census tracts, and counties.

Although these crosswalks are only "from block groups," they're designed to facilitate analysis at any of the target levels: block groups, census tracts, or counties. For example, to generate data for analysis of 2020 tracts, one could allocate 2006-2010 ACS data for block groups to 2020 tracts using the corresponding crosswalk. Then the output will be directly comparable with tract data in 2016-2020 ACS tables. And by starting from block groups (the lowest available level of ACS summary data), the output will also be more accurate.

The Census Bureau made very few changes to its definitions of census tracts and block groups between 2010 and 2019, and there were only a few county boundary changes, so these 2010-2020 crosswalks generally support bridging between the new 2020 ACS data and any ACS 5-year data release between 2010 and 2019. We provide more details on the few exceptions here.

For more information, and to download the files, see the Geographic Crosswalks page.

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Privacy-Protected 2010 Census Demonstration Data from the 2022-03-16 DHC Demonstration Data Product

March 29, 2022

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run (2022-03-16 vintage) of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from their new system, the Census Bureau plans to release a series of demonstration data products. The recently released DHC Demonstration product was generated by the Census Bureau's most up-to-date version of their disclosure avoidance system and includes data on sex, age, race, Hispanic ethnicity, population in households, groups quarters, and housing units. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each demonstration data product. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of persons identifying as Hispanic).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The release of this new data product is based on the 2022-03-16 vintage of the DHC Demonstration Data.

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First release of 1980 block boundaries

March 8, 2022

NHGIS has released its first set of GIS boundary files for 1980 census blocks. These files provide a more accurate and complete representation of 1980 block boundaries than is available from the U.S. Census Bureau's 1992 TIGER/Line files, the only previously existing source of nationwide digital 1980 block definitions.

To derive the new boundary files, we begin from the 1992 TIGER/Line files and apply extensive manual editing, using paper maps from the 1980 census as a guide, to reconcile the many differences between the TIGER/Line blocks and 1980 census block summary data.

The new files are not yet available through the NHGIS Data Finder. They are instead provided through the 1980 Block Boundaries page along with complete documentation and block-level summary statistics.

This first version of the files covers 48 metropolitan areas, including Chicago, Philadelphia, San Francisco-Oakland, and 9 more of the 30 largest areas. We will extend the files to include more areas in future releases.

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Time Series Extended to 2020 Census & 2019 ACS

February 23, 2022

NHGIS has extended its collection of time series tables to include data from the 2020 Census Redistricting Data and from the American Community Survey 2019 5-Year Summary File.

Our geographically standardized tables now provide 1990, 2000, 2010 & 2020 data for 10 levels of 2010 census areas, including census tracts, block groups, and ZIP Code Tabulation Areas.

Our nominally integrated tables include data from 1790 through 2020, including two ACS 5-year periods: 2008-2012 (which maintains a decadal time interval, being centered on 2010) and 2015-2019 (currently the most recent ACS 5-year period).

More details on this release are provided in the NHGIS Revision History.

Complete documentation for NHGIS time series is provided on the Time Series Tables page.

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Blog post: Better maps with census centers of population

February 17, 2022

To make better maps of U.S. populations, census centers of population are a great, underused resource. Centers of population put symbols where the people actually are, revealing important features of the distribution.

NHGIS project manager Jonathan Schroeder shows why, with lots of maps, in a new IPUMS blog post.

You can get shapefiles for centers of population through the NHGIS Data Finder. They're available for states, counties, census tracts, and block groups and for 2000, 2010, and 2020.

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GIS file updates:   
2020 centers of population,   
2010 boundaries from 2020 TIGER/Line,   
2000 boundaries for Puerto Rico

January 21, 2022

NHGIS has updated its collection of GIS files with many new files and some important updates to existing files:

• New 2020 centers of population for states, counties, census tracts, and block groups
• New 2010 boundary files based on 2020 TIGER/Line files
• Updates to the 2000 boundary files based on 2010 TIGER/Line files, including the addition of Puerto Rico areas and new files for 2000 school districts (elementary, secondary, and unified) and subminor civil divisions
• New 2020 voting district boundary file

For more detail on all the updates, see the NHGIS Revision History.

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2020 GIS boundary files

August 19, 2021

NHGIS has released 137 new GIS boundary files based on 2020 TIGER/Line Shapefiles. The new files correspond to the geographic units identified in 2020 census data and 2020 American Community Survey data. The release includes nationwide files for 33 geographic levels and 104 state-specific files: 52 for block groups and 52 for blocks.

The GIS Files documentation page provides more information, including an overview of how NHGIS boundary files differ from the Census TIGER/Line data.

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2020 Census Redistricting Data

August 17, 2021

NHGIS has released all data from 2020 Census P.L. 94-171 Redistricting Data Summary Files. Six tables provide data on 63 race combinations by Hispanic/Latino origin, voting age population by race and ethnicity, group quarters type, and housing occupancy/vacancy.

The tables are available for 98 geographic levels, down to block groups and blocks.

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Privacy-Protected 2010 Census Demonstration Data from the 2021-06-08 PPMF (2020 Production Settings)

August 12, 2021

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run (2021-06-08 vintage) of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from trial versions of their new system, the Census Bureau plans to release a series of Privacy-Protected Microdata Files (PPMFs). The recently released PPMF was generated by the Census Bureau's most up-to-date version of their disclosure avoidance system. The disclosure avoidance settings used to produce this PPMF are the same as those used to produce the 2020 PL94-171 redistricting data. This PPMF only includes variables that support the production of the PL94-171 redistricting dataset. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each version of the PPMF. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of persons identifying as Hispanic).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The release of this new data product is based on the 2021-06-08 vintage of the PPMF.

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Crosswalks Between 2010 & 2020 Census Blocks

August 9, 2021

NHGIS has extended its collection of geographic crosswalks to include "forward" crosswalks from 2010 to 2020 census blocks and "backward" crosswalks from 2020 to 2010 census blocks.

With the forward crosswalks, users could begin now to prepare 2010 data for 2020 census areas (tracts, block groups, etc.), enabling direct 2010-2020 comparisons when the 2020 data becomes available. (The Census Bureau now plans to release the 2020 Redistricting Data files on August 12, 2021. NHGIS is preparing to process and release our versions of those data as soon as possible after that.)

These forward crosswalks are preliminary versions*, however, because the allocation weights in NHGIS crosswalks require data from the "target year" that are not yet available. E.g., for a 2010 block that corresponds to two 2020 blocks, NHGIS will base the final allocation weights on the 2020 densities of population and housing in the two target blocks. Because the 2020 block data have not yet been released, the preliminary forward crosswalk provides only area weights, indicating the proportion of each 2010 block's area lying in each 2020 block.

The weights in the backward 2020-2010 crosswalks are based on already-available 2010 block data, so they are now complete. With these crosswalks, users could estimate 2020 characteristics for 2010 areas (when 2020 data are available). This will enable comparing 2020 data with 1990 and 2000 data that are also standardized to 2010 geography, as in NHGIS standardized time series tables.

*UPDATE  (September 7, 2021): The preliminary versions of the forward crosswalks have now been replaced with complete versions that include both area weights and density-based weights.

For more information, and to download the files, see the Geographic Crosswalks page.

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Privacy-Protected 2010 Census Demonstration Data from the 2021-04-28 PPMF (epsilon 4.5)

May 1, 2021

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run (20210428 vintage) of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from trial versions of their new system, the Census Bureau plans to release a series of Privacy-Protected Microdata Files (PPMFs). The recently released PPMF is was generated by the Census Bureau's most up-to-date version of their disclosure avoidance system. The overall privacy loss budget for the PPMF is 4.5, with 4.0 allocated to person-level data and 0.5 allocated to housing unit-level data. This PPMF only includes variables that support the production of the PL94-171 redistricting dataset. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each version of the PPMF. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of persons identifying as Hispanic).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The release of this new data product is based on the third vintage (20210428) of the PPMF.

We encourage users to provide feedback about the demonstration data by emailing the Census Bureau at 2020DAS@census.gov. If you send input by email, you can also email a copy to IPUMS at nhgis+diffpriv@umn.edu.

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Privacy-Protected 2010 Census Demonstration Data from the 2021-04-28 PPMF (epsilon 12.2)

April 28, 2021

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run (20210428 vintage) of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from trial versions of their new system, the Census Bureau plans to release a series of Privacy-Protected Microdata Files (PPMFs). The recently released PPMF is was generated by the Census Bureau's most up-to-date version of their disclosure avoidance system. The overall privacy loss budget for the PPMF is 12.3, with 10.3 allocated to person-level data and 1.9 allocated to housing unit-level data. This PPMF only includes variables that support the production of the PL94-171 redistricting dataset. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each version of the PPMF. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of persons identifying as Hispanic).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The release of this new data product is based on the third vintage (20210428) of the PPMF.

We encourage users to provide feedback about the demonstration data by emailing the Census Bureau at 2020DAS@census.gov. If you send input by email, you can also email a copy to IPUMS at nhgis+diffpriv@umn.edu.

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Blog post: Mapping block-level segregation, 1980-2010

February 12, 2021

NHGIS staff are now working on extending our collection of block boundary data back to 1980 and 1970. A new IPUMS blog post presents a case study that uses NHGIS block data, including not-yet-published 1980 block boundaries, to map the distribution of Black residents in the Twin Cities from 1980 to 2010. The blog features an interactive web map that allows users to compare block data from different census years and overlay historical racial covenants and HOLC "redlining" zones.

From the blog:

The block-level changes since 1980 show a striking trend toward greater dispersion and integration of Black residents, but segregation persists; several neighborhoods still have uniformly low or high proportions of Black residents. By overlaying racial covenants and HOLC zones with the block data, we can also find cases where the historical discriminatory practices appear to have left a lasting imprint on the distribution of Black residents.

Amalea Jubara and Yaxuan Zhang, MPC Summer Diversity Fellows, prepared the data, maps, and text for the blog under the direction of Jonathan Schroeder (research scientist at IPUMS) and Ying Song (assistant professor, Department of Geography, Environment & Society, University of Minnesota).

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2015-2019 ACS 5-Year Summary File & 2019 GIS boundary files now available

January 13, 2021

NHGIS has added the 2015-2019 5-Year Summary File from the American Community Survey (ACS). Over 1,100 new tables are now available for geographic areas as small as block groups.

NHGIS has also released 85 GIS boundary files representing the areas summarized in the 2019 ACS 1-Year and 5-Year Summary Files. The new shapefiles are derived from the 2019 TIGER/Line Shapefiles from the U.S. Census Bureau. Geographic levels from the block group to the nation level are now available.

For more information, see the Revision History.

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Privacy-Protected 2010 Census Demonstration Data from the 2020-11-16 PPMF

November 18, 2020

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run (20201116 vintage) of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from trial versions of their new system, the Census Bureau plans to release a series of Privacy-Protected Microdata Files (PPMFs). The recently released PPMF corrects an error in the code that produced the 2010 Demonstration Data. This new PPMF only includes variables that support the production of the PL94-171 redistricting dataset. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each version of the PPMF. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of persons identifying as Hispanic).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The release of this new data product is based on the second vintage (20201116) of the PPMF.

We encourage users to provide feedback about the demonstration data by emailing the Census Bureau at 2020DAS@census.gov. If you send input by email, you can also email a copy to IPUMS at nhgis+diffpriv@umn.edu.

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NIST Challenge: How to Evaluate Quality of Privacy-Protected Data

October 29, 2020

Are you concerned (as we are) about how the Census Bureau's implementation of differential privacy for the 2020 Census will impact data quality? Here's an opportunity to help.

As Census Bureau technicians continue to work toward the final specifications for the 2020 Disclosure Avoidance System, they will use a variety of metrics to gauge accuracy and to identify which issues most need to be addressed. Which metrics they use may determine which features of 2020 data do or do not retain high quality.

To help ensure that the selection of metrics is optimized for a broad range of user needs, the Public Safety Communications Research Division (PSCR) of the National Institute of Standards and Technology (NIST) has announced a competition for the user community to help identify the most important and effective metrics:

We are reaching out to invite you, as a data user stakeholder, to participate in [a] crowdsourcing challenge: Better Meter Stick for Differential Privacy. With up to $29,000 in prizes, NIST is seeking evaluation metrics for measuring the quality and utility of privatized data. Winning solutions will be considered in the scoring metric design for the final sprint of NIST’s Differential Privacy Temporal Map Challenge.   

We are seeking your insight and perspective on evaluating how well data utility is maintained after privacy algorithms are applied to de-identify data sets. We are especially seeking evaluation metrics that represent a breadth of real world use cases, provide good discriminative power to distinguish between the ground truth and privatized data, and can assist algorithm developers in tracking down the sources of significant disparity between the privatized and ground truth data.   

We are providing multiple sample datasets for testing, an example solution, and extensive tips & tricks guidance for developing clear, powerful and easily used metrics that represent your needs for data quality.   

Winning metrics (with consent) will be gathered and made available to data privacy researchers for use far beyond the scope of this challenge.   

Think you’re up for the challenge? The NIST Better Meter Stick for Differential Privacy challenge is open to submissions until 5 January 2021! Submit your 2-page executive summary by November 30 2020 for an optional preliminary review and feedback. You can learn more and sign up to participate by visiting the challenge here. ...   

For more information, please feel free to check out:

• The Introductory Webinar recording here
• The Example Submission here
• And the Metrics Tips & Tricks guide here

We at IPUMS hope you'll consider submitting an entry!

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2019 ACS 1-Year Summary File now available

October 21, 2020

NHGIS has added the 2019 1-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2019 GIS boundary files soon. Until then, users may use the 2018 boundary files with 2019 tables for most geographic levels and areas.

For more information about this release, see the NHGIS Revision History and the ACS technical documentation.

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Privacy-Protected 2010 Census Demonstration Data from the 2020-09-17 PPMF

September 21, 2020

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run (20200917 vintage) of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from trial versions of their new system, the Census Bureau plans to release a series of Privacy-Protected Microdata Files (PPMFs). The recently released PPMF reflects algorithm modifications since the second 2010 Demonstration Data were released in June 2020. This new PPMF only includes variables that support the production of the PL94-171 redistricting dataset. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each version of the PPMF. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of persons identifying as Hispanic).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The release of this new data product is based on the second vintage (20200917) of the PPMF.

We encourage users to provide feedback about the demonstration data by emailing the Census Bureau at 2020DAS@census.gov. If you send input by email, you can also email a copy to IPUMS at nhgis+diffpriv@umn.edu.

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New Crosswalks for Allocating 1990 & 2000 Long-Form Data to 2010 Units

August 26, 2020

NHGIS has extended its collection of geographic crosswalks to include crosswalks from 1990 and 2000 block group parts (BGPs), the smallest units for which the Census Bureau published summary tables covering "long-form subjects" (e.g., income, education, employment, migration, commuting). Separate crosswalk files identify relationships from source BGPs to target 2010 block groups, census tracts, and counties, enabling users to produce high-quality tabulations of 1990 and 2000 characteristics for any of these 2010 census units.

The BGP crosswalks include four interpolation weights, indicating the expected proportions of each source zone's population, families, households, and housing units located in each target zone, so users can select an appropriate weighting variable for the distribution of interest (e.g., using household weights to allocate 1990 counts of high-income households to 2010 census tracts).

We have also added both nationwide and state-specific files for each type of crosswalk, including new state-specific files for our previously available block-to-block crosswalks.

For more information, and to download the files, see the Geographic Crosswalks page.

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Additional Privacy-Protected 2010 Census Demonstration Data

July 30, 2020

We have released an expanded batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

We added 12 tables and 3 geographic levels to our July 14, 2020, data release. The additional tables are:

1. P6. Race (Total Races Tallied)
2. P7. Hispanic or Latino Origin by Race (Total Races Tallied)
3. P14. Sex by Age for the Population Under 20 Years
4. P12A. Sex by Age (White Alone)
5. P12B. Sex by Age (Black or African American Alone)
6. P12C. Sex by Age (American Indian and Alaska Native Alone)
7. P12D. Sex by Age (Asian Alone)
8. P12E. Sex by Age (Native Hawaiian and Other Pacific Islander Alone)
9. P12F. Sex by Age (Some Other Race Alone)
10. P12G. Sex by Age (Two or More Races)
11. P12H. Sex by Age (Hispanic or Latino Origin)
12. P12I. Sex by Age (White Alone, Not Hispanic or Latino)

The additional geographic levels are:

1. American Indian Area/Alaska Native Area/Hawaiian Home Land (by State--County--Census Tract)
2. County (by State--American Indian Area/Alaska Native Area/Hawaiian Home Land)
3. County Subdivision (by State--American Indian Area/Alaska Native Area/Hawaiian Home Land--County)

We encourage users to provide feedback about the demonstration data by emailing the Census Bureau at 2020DAS@census.gov. If you send input by email, you can also email a copy to IPUMS at nhgis+diffpriv@umn.edu.

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Privacy-Protected 2010 Census Demonstration Data

July 14, 2020

We have released a new batch of demonstration data files linking together two versions of 2010 Census summary tables:

1. Original tables from the 2010 Census Summary Files
2. New tables derived from a recent trial run of the Census Bureau's 2020 Disclosure Avoidance System (DAS) applied to the original 2010 Census responses

The Census Bureau is experimenting with ways to apply the framework of "differential privacy" to improve privacy protections for 2020 Census data. To help data users assess output from trial versions of their new system, the Census Bureau plans to release a series of Privacy-Protected Microdata Files (PPMFs). The recently released first PPMF reflects algorithm modifications since the first 2010 Demonstration Data were released in October 2019. To make these data easier to use, IPUMS NHGIS is creating a Privacy-Protected Summary File (PPSF) from each version of the PPMF. Our PPSF consists of tabulations where each row represents a geographic unit and each column represents a summary statistic (e.g., the count of females age 0-4).

To facilitate comparisons, we link comparable data from the PPSF and the original 2010 Census Summary File 1. These linked files comprise the IPUMS NHGIS Privacy-Protected 2010 Census Demonstration Data. The first release of this new data product is based on the first vintage (20200527) of the PPMF.

We encourage users to provide feedback about the demonstration data by emailing the Census Bureau at 2020DAS@census.gov. If you send input by email, you can also email a copy to IPUMS at nhgis+diffpriv@umn.edu.

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2018 GIS boundary files now available

April 2, 2020

NHGIS has released 85 shapefiles compatible with the 1- and 5-year 2018 American Community Survey (ACS) datasets. The new shapefiles are derived from the 2018 TIGER/Line Shapefiles from the U.S. Census Bureau. Geographic levels from the block group to the nation level are now available.

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UPDATED 2010 CENSUS DEMONSTRATION DATA FOR DIFFERENTIAL PRIVACY

February 4, 2020

We updated the NHGIS demonstration data to account for a processing error related to two tables in the 1st segment of the Demographic and Housing Characteristics Demonstration File. When NHGIS processed the 1st segment, we applied the wrong variable names to tables P20 (Households by Type and Presence of Own Children Under 18) and P22 (Household Type by Age of Householder). This application led to incorrect comparisons between the 2010 Summary File 1 data and the 2010 Demonstration Data for these two tables.

The updated data files drop table P20, apply the correct variable names to P22, and include table P23 (Households by Presence of People 60 Years and Over by Household Type). We have updated the codebooks to reflect the content of the data files.

We apologize for the error.

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2014-2018 ACS 5-Year Summary File now available

January 28, 2020

NHGIS has added the 2014-2018 5-Year Summary File from the American Community Survey (ACS). Over 1,100 new tables are now available for geographic areas as small as block groups.

We expect to release 2018 GIS boundary files that correspond to the the 2018 1-year and 5-year ACS data tables very soon. In the meantime, for most areas and for most geographic levels, it is possible to map and analyze 2018 ACS data by joining the data with the 2017 boundary files.

For more information, see the Release Log.

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NHGIS API, Version 1.0

December 17, 2019

The IPUMS NHGIS API is now publicly available! With the new Version 1.0, any IPUMS user registered with NHGIS can explore NHGIS metadata and create NHGIS data extracts programmatically via the API. Learn more about the IPUMS API program here. You can also share feedback or keep up with the conversation through the IPUMS API Users Forum.

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Webinar on Time Series Tables

November 25, 2019

In a webinar on November 20, 2019, NHGIS staff member Jonathan Schroeder presented an overview of time series tables, including comparisons with alternative sources of standardized time series. If you were unable to attend, we have posted the video and slides.

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2010 Census Demonstration Data for differential privacy

November 5, 2019

To protect the confidentiality of 2020 Census respondents, the U.S. Census Bureau plans to use a framework termed "differential privacy". The IPUMS team is concerned about the potential impacts of this approach on the scope and quality of census data products.

To help data users assess the impacts of differential privacy, the Census Bureau has released 2010 demonstration data products, which supply differentially private versions of 2010 data. To facilitate comparisons between the original and differentially private versions of the 2010 data, NHGIS is providing subsets of the demonstration data linked together with the original data.

We encourage users to provide feedback about the demonstration data by emailing the Census Bureau and through the Workshop on 2020 Data Products (December 11-12, 2019) organized by the Committee on National Statistics. If you send input by email, you can also email a copy to IPUMS at nhgis+diffpriv@umn.edu.

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2018 ACS 1-Year Summary File now available

October 23, 2019

NHGIS has added the 2018 1-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2018 GIS boundary files soon. Until then, users may use the 2017 boundary files with 2018 tables for most geographic levels and areas.

For additional information, see the Release Log.

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Marriage & divorce data for 1867-2010

June 11, 2019

NHGIS has added a new dataset (1867_2010_cMD) that provides counts of marriages and divorces by county for a selection of years from 1867 to 2010.

Specifically, the dataset includes counts for 1867-1886, 1890, 1900, 1916, 1922-1932, 1949-1950, 1952, 1957-1987, 2000, and 2010. No marriage counts are available for 1890 or 1900, and no divorce counts are available for 1949.

We thank our partners at the National Center for Family and Marriage Research (NCFMR) at Bowling Green State University for compiling and sharing this valuable resource!

Thanks also to the Eunice Kennedy Shriver National Institute of Child Health and Human Development (NICHD) for funding this work.

For complete information on data sources, see the Tabular Data Sources page.

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Centers of population for states, counties, tracts, and block groups

January 23, 2019

NHGIS has released new GIS point files depicting the 2000 and 2010 centers of population for states, counties, census tracts, and block groups.

NHGIS derived these points from the U.S. Census Bureau's Centers of Population data files.

Each point represents the mean center of population within the corresponding area, computed as an average of census block locations, weighted by block population, using a simple spherical model of the Earth surface. As described in the Census Bureau's Centers of Population Computation documentation: "The center of population is the point at which an imaginary, weightless, rigid, and flat (no elevation effects) surface representation of [a geographic area] would balance if weights of identical size were placed on it so that each weight represented the location [of] one person."

More information on the derivation of these points is available in the NHGIS GIS Files documentation.

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2017 GIS boundary files now available

January 23, 2019

NHGIS has released 85 shapefiles compatible with the 1- and 5-year 2017 American Community Survey (ACS) datasets. The new shapefiles are derived from the 2017 TIGER/Line Shapefiles from the U.S. Census Bureau. Geographic levels from the census block group to the nation level are now available.

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2013-2017 ACS 5-Year Summary File now available

January 17, 2019

NHGIS has added the 2013-2017 5-Year Summary File from the American Community Survey (ACS). Over 1,100 new tables are now available for geographic areas as small as block groups.

We expect to release 2017 GIS boundary files that correspond to the the 2017 1-year and 5-year ACS data tables very soon. In the meantime, for most areas and for most geographic levels, it is possible to map and analyze 2017 ACS data by joining the data with the 2016 boundary files.

For more information, see the Release Log.

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2017 ACS 1-Year Summary File now available

November 14, 2018

NHGIS has added the 2017 1-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2017 GIS boundary files soon. Until then, users may use the 2016 boundary files with 2017 tables for most geographic levels and areas.

For additional information, see the Release Log.

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Webinar on IPUMS NHGIS

November 12, 2018

We held a webinar describing IPUMS NHGIS on Friday, November 9, 2018. The webinar provided an overview of the NHGIS data collection and a demonstration of the data access system. If you were unable to attend, we have posted the video and slides.

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Faster processing of time series tables

August 14, 2018

NHGIS now employs an Apache Spark cluster-computing framework to process time-series data requests, achieving major reductions in processing time. In our testing, the NHGIS system now completes requests for geographically standardized time series 2-4 times faster, and it completes requests for nominally integrated time series 5-20 times faster, reducing the processing time for some very large requests from a few hours to a few minutes.

This update, along with our October 2017 update that implemented Spark-based processing of source table requests, completes the transition of the NHGIS data extract system to a parallel-processing framework for all table data requests. We hope users enjoy the shorter wait times and the quicker access to NHGIS data!

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Vital statistics for 1970-2007

April 2, 2018

NHGIS has added one new dataset (1970_2007_cVS) summarizing births and deaths for counties, states, and the nation, for 1970, 1975, 1980, 1985, and annually from 1990-2007. The new datasets include a range of tables, covering births, deaths, and infant deaths in total.

This is the third and final planned release of vital statistics datasets, filling out NHGIS's collection of state and county vital statistics data for most years from 1915 through 2007.

For more information, see the Release Log.

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Vital statistics for 1939-1972

February 6, 2018

NHGIS has added two new datasets (1939_1959_cVS and 1959_1972_cVS) summarizing annual births and deaths for counties, states, and the nation, 1939-1972. The new datasets include a range of tables, covering births, deaths, stillbirths and infant deaths in total and by race, and counted separately by place of occurrence and place of residence.

This is the second release in a planned series that will extend NHGIS's collection to include state and county vital statistics data for most years from 1915 through 2007.

For more information, see the Release Log.

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2012-2016 ACS 5-Year Summary File & 2016 boundary files now available

December 21, 2017

NHGIS has added the 2012-2016 5-Year Summary File from the American Community Survey (ACS). Over 1,000 new tables are now available for geographic areas as small as block groups.

NHGIS has also released 85 shapefiles compatible with the 1- and 5-year 2016 American Community Survey (ACS) datasets. The new shapefiles are derived from the 2016 TIGER/Line Shapefiles from the U.S. Census Bureau. Geographic levels from the census block group to the nation level are now available.

Please note that ACS population thresholds cause incomplete correspondence between the shapefile records and the 1-year tabular data. For example, the 1-year ACS tables include no records for areas with populations less than 65,000, but the shapefiles include all areas, regardless of population.

For more information, see the Release Log.

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Vital statistics for 1915-1941

December 21, 2017

NHGIS has added a new dataset (code: 1915_1941_cVS) summarizing annual births and deaths from 1915 through 1941. The data are derived from the Census Bureau's vital statistics annual reports for states (including territories) and counties. The new dataset includes 21 variables organized into 14 tables, covering births, deaths, stillbirths and infant deaths in total and by race.

This is the first release in a planned series that will extend NHGIS's collection to include state and county vital statistics data for most years through 2007.

For more information, see the Release Log.

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2016 ACS 1-Year Summary File now available

November 30, 2017

NHGIS has added the 2016 1-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2016 GIS boundary files soon. Until then, users may use the 2015 boundary files with 2016 tables for most geographic levels and areas.

For additional information, see the Release Log.

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Faster processing of table requests

October 17, 2017

With the release of Version 2.0 of its extract engine, NHGIS now employs an Apache Spark cluster-computing framework to process extracts, achieving major reductions in processing time for large data requests. For example, in our testing, extracts of nationwide census block data tables run 5 to 30 times faster with the new system, in some cases reducing processing time from a few hours to a few minutes.

This upgrade mainly affects the processing of NHGIS "source tables"--not time series tables or GIS files--and some types of requests (those involving large numbers of datasets, geographic levels, and/or breakdowns) may still require longer times to complete. We plan to implement Spark-based processing of time series tables soon.

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Environmental summaries for counties and census tracts

October 13, 2017

NHGIS has released its first set of environmental summaries. Users may now download land cover summaries for 2015 counties and 2000, 2010, and 2015 census tracts, or climate summaries for counties.

The land cover data come from the National Land Cover Database (NLCD), which is derived from 30-meter resolution Landsat imagery. The NLCD summaries identify the area and proportion of area covered by each of 16 land cover classes in 2001, 2006, and 2011.

The climate data summarize precipitation and minimum, maximum, and mean temperatures from the PRISM Climate Group. The climate summaries are available for monthly and annual time steps from 1895-2014 and for 30-year normals covering the 1981-2010 time period.

For more information, or to download the files, see the new Environmental Summaries resource page.

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1900-2015 place points

October 12, 2017

NHGIS has released GIS point files depicting the locations of incorporated, unincorporated, and census-designated places from 1900 to 2015.

The new files identify the places that are listed in the U.S. Census Bureau's published tables for each decennial census between 1900 and 2010 and for each American Community Survey release between 2009 and 2015.

To find the place point files in the Data Finder, first apply a "Place" Geographic Levels filter or a Years filter for one of the covered years and then look under the GIS BOUNDARY FILES tab for GIS files with a geographic level of "Place (Points)".

For detailed information on the derivation and content of NHGIS place point files, see the Point Files documentation page.

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1990 data for 2010 units in Time Series Release 8

October 5, 2017

With Time Series Release 8.0, NHGIS has extended its collection of geographically standardized tables to include 1990 data (as well as 2000 and 2010) for 10 levels of 2010 census units, from states down to block groups.

The standardized 1990 data, like our existing standardized 2000 data, are derived entirely from census block data, ensuring a generally high level of accuracy.

To find the new standardized tables in the Data Finder, first apply a Years filter for 1990 and then look under the TIME SERIES TABLES tab for tables that are "Standardized to 2010."

In addition to the new standardized tables, Release 8.0 includes 14 new nominally integrated tables and updates to 20 existing tables. Highlights include:

• New tables using simplified "single race/ethnicity" categories, enabling more direct comparisons of race data across time
• Support for subtraction in the construction of time series, enabling the coverage of more categories for more years. For example, Urban/Rural tables now include both rural and urban counts for 1970.
• Nineteen new tables supplying housing counts by ethnicity, race, and tenure

For more information on the updates in this release, see the Release Log. For detailed information on NHGIS time series tables, see the Time Series Tables Documentation.

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Crosswalks from 1990 & 2000 blocks to 2010 blocks

August 16, 2017

NHGIS now provides geographic crosswalk files to support the allocation of summary data from one census year to another. At this time, NHGIS provides crosswalks for two settings: 2000 blocks to 2010 blocks and 1990 blocks to 2010 blocks. We plan to add more crosswalks in future releases.

The interpolation weights given in the crosswalks are the same weights that NHGIS uses to produce geographically standardized time series tables.

The 2000-to-2010 interpolation uses 2010 block population and housing densities, 2010 road data, and 2001 land cover data to model the distribution of 2000 block characteristics among intersecting 2010 blocks.

The 1990-to-2010 interpolation uses estimated 2000 densities from the 2000-to-2010 model to model the distribution of 1990 block characteristics among intersecting 2010 blocks. It also uses an advanced spatial overlay scheme to avoid assigning weights to the false 1990-2010 intersections that are artifacts of improvements in Census block boundary definitions.

To download the crosswalk files, see the new Geographic Crosswalks user-resource page.

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New article on NHGIS standardized time series

February 8, 2017

The March 2017 issue of Computers, Environment and Urban Systems includes an article by NHGIS researcher Jonathan Schroeder, titled "Hybrid areal interpolation of census counts from 2000 blocks to 2010 geographies", which explains and assesses the interpolation model that NHGIS uses to allocate 2000 census block counts to 2010 census units for our geographically standardized time series tables. The article compares applications of 18 separate models to a nationwide sample of 2000 block pairs, finding that the selected hybrid model, as used by NHGIS, improves substantially on the alternatives.

A pre-print version of the article is also available through Schroeder's profile page.

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2011-2015 ACS 5-Year Summary File & 2015 boundary files now available

January 3, 2017

NHGIS has added the 2011-2015 5-Year Summary File from the American Community Survey (ACS). Over 1,000 new tables are now available for geographic areas as small as block groups.

NHGIS has also released 85 shapefiles compatible with the 1- and 5-year 2015 American Community Survey (ACS) datasets. The new shapefiles are derived from the 2015 TIGER/Line Shapefiles from the U.S. Census Bureau. Geographic levels from the census block group to the nation level are now available.

Please note that ACS population thresholds cause incomplete correspondence between the shapefile records and the 1-year tabular data. For example, the 1-year ACS tables include no records for areas with populations less than 65,000, but the 2015 shapefiles include all areas, regardless of population.

For additional information, see the Release Log.

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2015 ACS 1-Year Summary File now available

November 3, 2016

NHGIS has added the 2015 1-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2015 GIS boundary files soon. Until then, users may use the 2014 boundary files with 2015 tables for most geographic levels and areas.

For additional information, see the Release Log.

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Time Series Release 7: Hispanic/Non-Hispanic cross tabulations, Travel Time & more

September 28, 2016

With Time Series Release 7, NHGIS has added 34 new time series tables to its collection.

Newly covered subjects include Commuters by Travel Time to Work, Aggregate Travel Time to Work, and Persons by Hispanic or Latino Origin by Sex, Age, and Race in various combinations.

For additional information, see the Release Log.

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New agricultural data for 1920, 1925, 1930 & 1935

July 28, 2016

NHGIS has added 4 new datasets providing detailed summary statistics from the 1920, 1925, 1930 & 1935 Censuses of Agriculture. The new datasets (1920_cAg, 1925_cAg, 1930_cAg & 1935_cAg) include over 3,000 variables, organized into 594 tables, covering a broad range of agricultural subjects for counties, states, and the nation.

This is the first release in a planned series that will eventually extend NHGIS's collection to include detailed data from all U.S. Censuses of Agriculture through 2012. Previously, NHGIS included agricultural data only for decennial years from 1840 through 1950, and for 1920 and later, the NHGIS collection covered only a limited selection of subjects.

For more information, see the Release Log.

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Interactive tract & place web maps now available

February 19, 2016

NHGIS has added interactive web maps for the census tract and place geographic levels. These maps highlight the availability and comparability of NHGIS boundary data for these two levels across time. Additional information can be found on the Data Availability page.

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Webinar on time series tables now available

January 4, 2016

Users who would like to learn more about NHGIS time series tables, particularly ournew geographically standardized tables, can now view a one-hour webinar, originally delivered in December 2015 by NHGIS researcher Jonathan Schroeder to the New Jersey, New York, and Pennsylvania State Data Center Networks. Cornell University hosts a recording of the webinar here:

• NHGIS Time Series Tables: Now Including 2000 Data for 2010 Census Areas

The NHGIS Time Series Tables page also provides a link to the same recording.

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2014 ACS 5-Year Summary File & GIS boundary files now available

December 16, 2015

NHGIS has added the 2014 5-Year Summary File from the American Community Survey (ACS). Over 1,000 new tables are now available for geographic areas as small as block groups.

NHGIS has also released 85 shapefiles compatible with the 1- and 5-year 2014 American Community Survey (ACS) datasets. The new shapefiles are derived from the 2014 TIGER/Line Shapefiles from the U.S. Census Bureau. Geographic levels from the census block group to the nation level are now available.

Please note that ACS population thresholds cause incomplete correspondence between the shapefile records and the 1-year tabular data. For example, the 1-year ACS tables include no records for areas with populations less than 65,000, but the 2014 shapefiles include all areas, regardless of population.

For additional information, see the Release Log .

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2014 ACS 1-Year Summary File now available

October 26, 2015

NHGIS has added the 2014 1-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2014 GIS boundary files soon. Until then, users may use the 2013 boundary files with 2014 tables for most geographic levels and areas.

For additional information, see the Release Log .

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2000 data for 2010 block groups, ZIP code areas, metro areas, and more

September 21, 2015

With Time Series Release 6.1, NHGIS has extended its geographically standardized tables to cover block groups, ZIP Code Tabulation Areas (ZCTAs), core based statistical areas (including both metropolitan and micropolitan statistical areas), urban areas, congressional districts, places, county subdivisions, counties, and states, in addition to the existing data for census tracts.

These 65 tables now provide high-quality block-based estimates for a broad range of 2000 characteristics in 2010 census units at 10 geographic levels, along with lower and upper bounds, making it possible to measure decadal changes more accurately, and for more areas, than has ever before been possible.

To find the standardized tables in the Data Finder , first apply a Geographic Levels filter for one of the levels listed above. Then look under the Time Series Tables tab for tables that are "Standardized to 2010."

For detailed information on NHGIS time series tables, see the Time Series Tables Documentation .

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2000 data for 2010 census tracts in Time Series Release 6

August 5, 2015

With Time Series Release 6.0, NHGIS has added 65 geographically standardizedtables that each provide 2000 and 2010 data for 2010 census tracts. To generate the 2000 data, NHGIS reaggregates data from 2000 census blocks. Where a 2000 block intersects multiple 2010 tracts, NHGIS applies interpolation to estimate how the 2000 block's characteristics are distributed among the 2010 tracts.

To help users interpret the uncertainty in interpolated estimates, the standardized tables include lower and upper bounds for each estimate based on the spatial relationships between 2000 blocks and 2010 tracts.

To find the new standardized tables in the Data Finder, first apply a Geographic Levels filter for Census Tract data and then look under the Time Series Tables tab for tables that are "Standardized to 2010." To view all of the standardized tables together, click twice on the Geographic Integration column header, which will sort the standardized tables to the top.

In addition to the new standardized tables, Release 6.0 includes 21 new nominally integrated tables, as well as several updates to existing tables. For more information, see the Release Log. For detailed information on NHGIS time series tables, see theTime Series Tables Documentation.

We plan to extend the standardized tables soon to cover more 2010 census geographic levels, so stay tuned!

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New 2013 GIS boundary files

February 25, 2015

NHGIS has released 85 shapefiles compatible with the 1, 3, and 5-year 2013 American Community Survey (ACS) datasets. The new shapefiles are derived from the 2013 TIGER/Line Shapefiles from the U.S. Census Bureau. Geographic levels from the census block group to the nation level are now available.

Please note that ACS population thresholds cause incomplete correspondence between the shapefile records and the 1 and 3-year tabular data. For example, the 1-year ACS tables include no records for areas with populations less than 65,000, but the 2013 shapefiles include all areas, regardless of population.

In addition, the Release Log highlights 6 revised and 3 other new files also included in this release.   
 

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New "Overview of NHGIS Datasets"

January 12, 2015

The newly added Overview of NHGIS Datasets lists all available table datasets along with information on data sources and on the number of tables, geographic levels, and breakdowns available for each dataset.

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2013 ACS 5-Year Summary File now available

December 18, 2014

NHGIS has added the 2009-2013 5-Year Summary File from the American Community Survey (ACS). Over 1,000 new tables are available for geographic areas as small as block groups. These data will correspond to the soon to be released 2013 shapefiles on NHGIS.   

For additional information, see the Release Log.

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New 2009 & revised 2010 GIS boundary files

November 20, 2014

NHGIS has released 116 updated or new GIS Boundary files. All shapefiles with a basis of TIGER/Line 2009+ are included in this new release, as are 32 revised state-specific block boundary files with basis of TIGER/Line 2010+ and two revised boundary files with basis of TIGER/Line 2008+.

The 82 new shapefiles with the TIGER/Line 2009+ basis correspond to either the 2009 ACS datasets or, for tracts and block groups, the 2000 Census. For additional information on this issue and the other released shapefiles, see the Release Log .   
 

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2013 ACS 3-Year Summary File now available

November 20, 2014   
NHGIS has added the 2013 3-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 20,000 or more residents. NHGIS will also supply 2013 GIS boundary files soon. Until then, users may use the 2012 boundary files with 2013 tables for most geographic levels and areas.   

For additional information, see the Release Log.

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Time Series Release 5: 17 new tables

October 16, 2014

With Time Series Release 5, NHGIS has added 17 new time series tables to its collection. Newly covered subjects include Poverty Status, Ratio of Income to Poverty Level, Means of Transportation to Work, and Households by Household Type.

For additional information, see the Release Log or the Time Series Documentation.

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2013 ACS 1-Year Summary File now available

October 16, 2014

NHGIS has added the 2013 1-Year Summary File from the American Community Survey (ACS). Over 1,300 new tables are now available for geographic areas with 65,000 or more residents. NHGIS will also supply 2013 GIS boundary files soon. Until then, users may use the 2012 boundary files with 2013 tables for most geographic levels and areas.

For additional information, see the Release Log .

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2009 ACS 5-Year Summary File now available

September 24, 2014

NHGIS has added the 2005-2009 5-Year Summary File from the American Community Survey (ACS). Nearly 1,000 new tables are available for geographic areas as small as block groups. These data will correspond to the soon to be released 2009 shapefiles on NHGIS.

For additional information, see the Release Log .

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Improved breakdown codes

April 15, 2014

NHGIS has made several improvements to its breakdown coding scheme. (See the FAQ for an explanation of NHGIS breakdowns.) The most significant changes:

• Previously, breakdown codes in NHGIS data files were all 4 characters long. Now, to reduce noise in column identifiers, breakdown codes may be 2, 3, or 4 characters long depending on how many characters are needed to uniquely identify all breakdown combinations in use by a given dataset.
• Previously, the ordering of codes was somewhat arbitrary, determined by the sequence of breakdowns in the NHGIS metadata database. Now, codes are ordered according to their original logical sequence.
• Previously, in multi-year datasets like County Business Patterns, codes varied by both breakdown and year, so a single industry breakdown category would have different codes in different years. Now, within each dataset, a breakdown has a single code across all years, making it easier to identify files and columns associated with the same breakdown.

Note: as a consequence of these updates, most breakdowns have new codes. Users who would like to re-obtain previous data requests with codes that match the current codes may simply resubmit their older requests through the Extracts History page.

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Time series now include 2008-2012 ACS data

February 26, 2014

With Release 4.1 of time series tables, NHGIS has updated all tables that include American Community Survey (ACS) statistics to use 2012 5-year data instead of 2011 5-year data.

This change affects past data requests as well as new requests: users who return to the NHGIS Extracts History page and resubmit a prior request of time series tables will now receive new 2012 5-year data and not 2011 5-year data. Users may still find and select individual tables from the original 2011 ACS 5-year Summary Files by searching under the Data Finder's "source tables" tab.

Because the 2008-2012 period is centered on the year 2010, we believe it is the most suitable ACS period for use in decade-interval time series. Therefore, this update should be the last of its kind. NHGIS may in the future release new time series tables that include ACS data from other time periods, but there are no plans to again swap old data with new.

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2012 ACS 5-Year Summary File now available

February 17, 2014

NHGIS has added the 2008-2012 5-Year Summary File from the American Community Survey (ACS). Over 1,000 new tables are available for geographic areas as small as block groups. These data correspond to the previously released 2012 shapefiles on NHGIS.

These data, for the first time within a 5-Year ACS dataset, include tables on health insurance coverage. For additional information, see the Release Log.

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2012 ACS 3-Year Summary File now available

November 21, 2013   
NHGIS has added the 2010 - 2012 3-Year Summary File from the American Community Survey (ACS). Over 1,400 new tables are now available for geographic areas with populations exceeding 20,000, the minimum set by the US Census Bureau for the 3-year data. These data also correspond to the 2012 shapefiles recently released.

For additional information, see the Release Log.

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New 2012 & improved 2000 GIS boundary files

November 6, 2013

NHGIS has released 105 new GIS boundary files including 2012 files based on 2012 TIGER/Line Shapefiles and improved 2000 files based on 2010 TIGER/Line Shapefiles from the U.S. Census Bureau.

The 34 new 2012 shapefiles correspond to the already released 2012 American Community Survey 1-Year dataset and the soon-to-be released 3- and 5-Year datasets. The Release Log provides a complete list of the new 2012 files.

The 71 new 2000 shapefiles, based on 2010 TIGER/Line Files, correspond to the 2000 Census datasets. These files are more spatially accurate than the shapefiles based on 2000 TIGER/Line files due to the Census Bureau’s MAF/TIGER Accuracy Improvement Project. The Release Log provides a complete list of the new 2000 files.

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Time Series Release 4: 47 new tables

October 2, 2013

With Time Series Release 4, NHGIS has added 47 new time series tables to its collection. Newly covered subjects include Median Age, Place of Birth, Educational Attainment, Labor Force and Employment Status, Family Income, and Per Capita Income.

For additional information, see the Release Log or the Time Series Documentation.

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2012 ACS 1-Year Summary File now available

October 2, 2013

NHGIS has added the 2012 Summary File from the American Community Survey (ACS). Over 1,400 new tables are now available for many different geographic levels. NHGIS will also supply 2012 GIS boundary files soon. Until then, users may use the 2011 boundary files with 2012 tables for most geographic levels.

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New "time varies by column" layout for time series

August 7, 2013

NHGIS now provides a third layout option for time series tables in addition to the existing options of "time varies by file" and "time varies by row." The new "time varies by column" option places data for different times in separate columns within one file. For example, a table of state-level 2000 and 2010 census data is delivered in one file with one row for each state and two columns for each time series: one column for 2000 and one column for 2010.

NOTE: this layout matches area units across time according to area names and codes only without regard to geographic relationships. A single row may provide statistics for distinctly different areas at different times in cases where a matched code refers to distinct areas at different times.

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Improved topic filtering

August 7, 2013

NHGIS has completely revised and verified its topic filtering system. The new set of selectable topics more closely and completely represents the topics available in NHGIS data, and we have thoroughly reviewed associations between topics and tables to help ensure that all relevant tables--and only relevant tables--appear for any selected topics.

Using the new topics, this summary of available NHGIS data tables indicates which topics are covered across time by NHGIS data source.

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2011 GIS boundary files now available

May 16, 2013

NHGIS has released shapefiles compatible with the 1, 3, and 5-year 2011 American Community Survey (ACS) datasets. The new shapefiles are derived from the 2011 TIGER/Line Shapefiles from the U.S. Census Bureau. Geographic levels from the census block group to the nation level are now available.

Please note that ACS population thresholds cause incomplete correspondence between the shapefile records and the 1 and 3-year tabular data. For example, the 1-year ACS tables include no records for areas with populations less than 65,000, but the 2011 shapefiles include all areas, regardless of population.

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Streamlined NHGIS shapefiles now available

May 16, 2013

NHGIS shapefiles now have a more streamlined, unified structure. Previously, NHGIS provided boundaries in separate shapefiles for the Contiguous U.S., Alaska, Hawaii, and Puerto Rico. Now, for each geographic level larger than block groups, NHGIS includes all areas in one unified shapefile, simplifying many file management and data analysis tasks.

For additional information on this change and some other minor revisions, see theRelease Log.

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New time series tables including ACS data

April 8, 2013

With two recent releases, NHGIS now provides 27 additional time series tables in its collection. Highlights of Release 2.0 include urban/rural counts and totals for households and families. Release 3.0 is the first to include data from the American Community Survey, using the 5-year 2007-2011 data to produce tables on marital status, nativity, and median household income.

For additional information, please see the Release Log or the Time Series Documentation.

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New SABINS data released

April 3, 2013

The Minnesota Population Center and the College of William & Mary are pleased to announce a new release of 2009-2010 school attendance boundaries. The Minnesota Population Center re-processed all data released in September 2012 and added additional attendance boundaries. The database contains 200,155 school attendance boundaries for 6,058 school districts.

For more information, see the Release Log on the SABINS website.

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Realigned GIS boundary files now available

February 8, 2013

NHGIS has added realigned GIS boundary files for counties (1790-2000) and tracts (1910-2000). Because the Census Bureau made major accuracy improvements to TIGER/Line features between the 2000 and 2008 TIGER/Line releases, the original NHGIS shapefiles based on 2000 TIGER/Line features are not comparable with newer TIGER/Line data. We therefore generated new boundary files by systematically realigning the boundaries for tracts and counties to fit with 2008 TIGER/Line features. When comparing historical county or tract data to 2010 or newer boundary files, it is advisable to use these realigned files.

Additional information on the realigned GIS boundary files can be found here.

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2011 ACS 1-, 3- and 5-Year Summary Files now available

January 28, 2013

NHGIS has added the 2011 1-Year, 3-Year and 5-Year Summary Files from the American Community Survey (ACS). Over 3,800 new tables are now available for many different geographic levels. NHGIS will be adding 2011 GIS shapefiles soon, but until then the existing 2010 shapefiles will join the 2011 tables with little to no complications for most geographic levels.

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Summary File 2 of the 2010 Census now available

December 10, 2012

NHGIS is excited to announce the availability of the 2010 Census Summary File 2. This dataset includes 71 tables with extremely detailed 100% count race/ethnicity breakdowns at the census tract and higher geographic levels.

For additional information, please review the Summary File 2 Technical Documentation found here.

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The 1st anniversary of the new NHGIS

November 5, 2012

The new NHGIS website celebrated its 1st anniversary last month. From day 1, the new website has been a hit!

Some of the most popular requests:

Most popular tables

1. "Total Population" from 2010 Census Summary File 1
2. "Persons" from 1990 Census Summary File 1
3. "Total Population" from 2000 Summary File 1

Most popular datasets

1. 1990 STF1 - 100% Data
2. 2010 SF1a - P & H Tables [Blocks & Larger Areas]
3. 2000 SF1a - 100% Data [Areas Larger Than Block Groups]

Most popular geographic levels

1. County
2. Tract
3. State

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Urban/Rural Update File for 2010 SF1 now available

October 30, 2012

NHGIS has released the 2010 Summary File 1 Urban/Rural Update File. This update adds data for urban area geographic levels, urban/rural tables, and urban/rural breakdowns.

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NHGIS featured in Planning

October 10, 2012

NHGIS is prominently featured in the October 2012 issue of Planning , the magazine of the American Planning Association. The article, "Demographic Data for a Changing Nation" highlights the unique features of NHGIS and explains how to use the website to access census tables, GIS files, and the new time series tables.

Update: November 6, 2012

Free online access to the article has ended, but APA members may still access the article here after logging in.Most others can access the article online or in print through their academic or local library.

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Time series tables now available

September 19, 2012

NHGIS has added time series tables to its data collection. Time series tables link together comparable statistics from multiple censuses in one table. The first release ismainly comprised of 100% count statistics from the 1970-2010 censuses for eight different geographic levels ranging from the nation down to census tracts. Planned future releases will also provide sample-based data, including the latest American Community Survey data.

For additional information, please review the Release Log or the Time Series Documentation page.

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2008-2010 ACS 3-Year Summary File now available

July 10, 2012

NHGIS has added the 2008-2010 3-Year Summary File from the American Community Survey (ACS). Over 1,400 new tables are now available for geographic areas with populations exceeding 20,000, the minimum set by the US Census Bureau for the 3-year data. For additional information on how NHGIS is handling the ACS datasets, including "." jam values, please review the release log here .

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2006-2010 ACS 5-Year Summary File now available

May 21, 2012

NHGIS has added the 2006-2010 5-Year Summary File from the American Community Survey (ACS). Over 900 new tables are now available for geographic levels ranging from block groups to the nation. For additional information on how NHGIS is handling the ACS datasets, including "." jam values, please review the release log here .

The next planned release will add the 2008-2010 3-Year data.

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2010 ACS 1-Year Summary File now available

April 9, 2012

NHGIS has added the 2010 1-Year Summary File from the American Community Survey (ACS). Over 1,400 new tables are now available for geographic areas with populations exceeding 65,000, the minimum set by the US Census Bureau for the 1-year data. For additional information on how NHGIS is handling the ACS datasets, including "." jam values, please review the release log here .

Additional ACS datasets will be released over the coming months. The next planned release will add the 2006-2010 5-Year data.

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NHGIS Panel Session at AAG Annual Meeting

Sunday, February 26, 2012 - 8 AM to 9:40 AM - Green Room, Hilton New York

NHGIS will be the focus of discussion during The Future of Historical U.S. Census Data: Charting the Course of the New NHGIS. Six panelists and the audience will discuss the past, present, and future of NHGIS. All conference attendees are welcome to attend and participate. User feedback is crucial to the evolution of NHGIS so let us know what you like and dislike about NHGIS and how we should move forward with new data and features. For complete information about this panel session, please go here .

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NHGIS unavailable January 28th

January 20, 2012

The NHGIS web extract system will be temporarily unavailable on Saturday, January 28th for IT upgrades. We apologize for any inconvenience this causes.

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2010 Census Summary File 1 now available

January 10, 2012

NHGIS is pleased to announce that 2010 Census Summary File 1 is now available for download. Summary File 1 includes 331 tables that offer detailed cross-tabulations of age, sex, race, household structure, housing units, and other related topics.

Most tables are tabulated at many geographic levels, ranging from the national level down to the block level.

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NHGIS announces conference exhibitor schedule

November 1, 2011

NHGIS and the Minnesota Population Center are hitting the road to help spread the news about our new website and to meet users in person. If you find yourself at any of the conferences listed below, please stop by the exhibitor area and say hello.   

Social Science History Association (SSHA) Annual Meeting in Boston, November 17-20 2011.   

Association of American Geographers (AAG) Annual Meeting in New York City, February 24-28 2012.   

American Educational Research Association (AERA) Annual Meeting in Vancouver, Canada, April 13-17 2012.   

American Planning Association (APA) National Conference in Los Angeles, April 14-17 2012.   

Population Association of America (PAA) Annual Meeting in San Francisco, May 3-5 2012.   

American Library Association (ALA) Annual Conference in Anaheim, California, June 21-26 2012.   

More conferences and workshops to be announced later!

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A new website and new 2010 data!

October 11, 2011

NHGIS is excited to announce a totally redesigned website. Several years in the making, the site provides a range of new features to make it easier to find and acquire data. Users can specify a set of data filters, in any combination, to narrow the thousands of tables down to just those they want. It is also possible to select and download data for any number of years, topics or geographic levels all at once.

Over the next year, NHGIS will also be expanding to include data from the 2010 Census and the American Community Survey, beginning with the 2010 PL 94-171 Redistricting Data, available now through the new website! Be sure to check back often for new data, site features, tutorials and documentation as we continue through several phases of planned site improvements.

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