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:

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

Decennial Census Summary Files (1960-2010)




Core summary files

Special & supplementary summary files


Core summary files

Special & supplementary summary files



County Business Patterns





American Community Survey

Technical Documentation

Subject Definitions