Compendia, Indexes and Portals
US, State, City
(links out to American Government & Politics guide)
Population, Housing, etc.
(links to the US Census guide)
(links out to the Polling and Public Opinion guide)
State Census Data (Historical)
1790 - 2010: Social Explorer.
Includes data from the Decennial Censuses (back to 1790), the American Community Survey (began in 2005), and religion data (back to 1980), along with other datasets not derived from the census.
1970-2010, reallocated to 2010 census boundaries: Social Explorer: Tables
U.S. Decennial Censuses on 2010 Geographies provide reallocated data from Decennial Censuses on 2010 geographies. Reallocation of decennial census data on 2010 geographies was performed using reallocation fractions from Longitudinal Tract Data Base (LTDB). Data is available on census tract, county, state and nation level geographies. The form of this survey, as well as the datasets and tables it contains, is kept similar to our corresponding Decennial Census surveys. See: Reallocating Census Data: How Social Explorer Makes Cross-Decade Comparisons Possible.
Note: Social Explorer does not include the non-decennial (intercensal) data from 1790 to 1945, generally known as the "Dubester set" (referencing a guide issued by the Library of Congress).
Prior to 1980, you may find that some areas are represented only by numeric codes. To identify the correct code for the area you need, see: https://www.census.gov/programs-surveys/metro-micro.html
1790 - National Historical Geographic Information System
The National Historical Geographic Information System (NHGIS) provides free online access to summary statistics and GIS boundary files for U.S. censuses and other nationwide surveys from 1790 through the present. Includes some geographies not represented in Social Explorer, above.
1960 - 2010: Geolytics CDROM
Note: The NCDB (National Change Database) disk includes 1970 - 2010 data, normalized to 2010 boundaries, down to the tract level. Unfortunately, Geolytics, a proprietary company, does not share it's methodology. Compare with Social Explorer Reallocated tables, above. See also: Validating Population Estimates for Harmonized Census Tract Data, 2000–2010 comparing NCDB with LTDB and NHGIS
2000 - 2010: American Factfinder (AFF).
2010: Data from the short form, sent to every household, and sample data from the American Community Survey, released in 1-year, 3-year and 5-year estimates. Please note: The 3-year estimates will be discontinued beginning with the next scheduled round (2012-2014).