Tabular Data Sources

Documentation (PDF format) for the digital sources of NHGIS data tables:

See also the Overview of NHGIS Datasets for summaries of the sources used for each dataset group.

Secondary Sources

Most NHGIS data tables for years prior to 1970 were originally entered into machine-readable digital formats from print publications by researchers at other institutions.

The documentation provided here describes the content and sources of the digital files that NHGIS has integrated into its system.

Scanned versions of many print census publications are also available through the U.S. Census Bureau's Census of Population and Housing Publications site.


1910, 1920 & 1930 Tract & Enumeration District Data

Summaries of data provided by Andrew Beveridge, Queens College, City University of New York:

1915-1972 Vital Statistics

The 1915-1967 vital statistics data are derived from printed annual reports of the U.S. Census Bureau (1915-1944) and the U.S. Public Health Service (1945-1967), most of which are available as PDF documents through this repository of the National Center for Health Statistics.

The 1968-1972 data are derived from individual-level microdata (either birth certificates or the Compressed Mortality File) from the National Center for Health Statistics.

Michael Haines at Colgate University provided NHGIS with the digital source data.

1970-2007 Vital Statistics

The 1970-2007 vital statistics data (in dataset 1970_2007_cVS) are derived from the USA Counties database of the U.S. Census Bureau, which includes birth and death data from the National Center for Health Statistics (NCHS) and population estimates from the U.S. Census Bureau Population Estimates program.

WARNING: Where county boundary changes occurred, the population estimates may be based on *different* county boundary definitions than the birth and death counts. In some cases, NHGIS has attempted to standardize the counts and rates to describe consistent county definitions. Elsewhere, NHGIS supplies a note to indicate where inconsistencies may occur. In these cases, the reported birth and death rates may be inaccurate and should be interpreted with caution.

NHGIS supplies flags and notes for these data records within output NHGIS data files. The flag text is provided completely within the output file. Notes are indicated by a code, and the codes are explained in the NHGIS 1970-2007 Vital Statistics Notes file.

Documentation for the original USA Counties database is provided through these Excel files:

1920-1935 Census of Agriculture Data

  • United States Agriculture Data, 1840-2012
    • This data series, compiled by Michael Haines (Colgate University), Price Fishback (University of Arizona) and Paul Rhode (University of Michigan), is also available as ICPSR Study 35206
    • Many of the datasets in this series were derived directly from ICPSR Study 3 or 2896, resulting in overlaps in series content.
    • NHGIS used this source for all of its detailed agricultural datasets (those with "cAg" codes) for 1920 and later years.

1920-1936 Bank Deposit Data

1940, 1950 & 1960 Tract Data

Back to Top

Decennial Census Summary Files (1960-2010)




Core summary files

Special & supplementary summary files


Core summary files

Special & supplementary summary files



Back to Top

County Business Patterns





Back to Top

American Community Survey

Technical Documentation

Subject Definitions

Back to Top