Tabular Data Sources

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

Secondary Sources (1790-1960)
Decennial Census Summary Files (1960-2010)
County Business Patterns (1970-2003)
American Community Survey (2009-2015)

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.

1790-1960

Historical Demographic, Economic and Social Data: The United States, 1790-2002 (ICPSR 2896)
- ICSPR Study 2896 is the secondary source of most of NHGIS's pre-1970 nation, state and county-level tables, including population, housing, manufacturing, and religious bodies data.
- This is also the source of all NHGIS agricultural census data for years 1840-1910 and for all tables in these NHGIS datasets: 1850_1959_cFV, 1920_cPHAM, 1920_sOccFarmer, 1930_cPAE, 1940_cPHAE, 1950_cPHA
- Updates in either the ICPSR or NHGIS data may have produced incomplete correspondence.
- For more information, see ICPSR's Study 2896 page.
Historical Demographic, Economic and Social Data: The United States, 1790-1970 (ICPSR 3)
- ICPSR Study 3 is an earlier version of ICPSR 2896 with a smaller scope and was used by NHGIS for its initial data development.
- Where ICPSR 2896 deviates from ICPSR 3, NHGIS data may correspond to either source, depending on which updates were available at the time NHGIS added the data.
- For more information, see ICPSR's Study 3 page.

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