Census Research Guide

1790-1930

Census of Population schedules (a line-by-line listing of each person living in the U.S. with personal information) available in microform in the Media Center (only for Iowa counties). Refer to Individual Households tab for further details.

1940 is available online at https://www.archives.gov/research/census/1940

1790-1840

Summary data is available in print Census, online PDFs, and extracted in several online databases (Social Explorer, ICPSR, Statistical Abstracts of the US)

1850-1950

Public-Use Microdata Samples (PUMS) were published. Some are available at ISU - use Quick Search to locate them. Also available online via IPUMS. Click on USA or International - then click on FAQ to see a basic explanation of what they are and what time period each of them covers.

1933

Census of American Business was first administered. In 1935, the name was changed to the Census of Business which, in 1967, became the Economic Census. Online data is available for 2003-present via Census.gov

1940

Census blocks became available with the first Census of Housing. (Block groups have an average of 39 blocks per group.) The "Long Form" was first used in 1940.

1947

Standard definitions for metropolitan areas are established.

1960

Tract maps first became available, but only for metropolitan areas. Use Quick Search to locate them at ISU. The Census Bureau also provides a page of information on locating 1990 & 2000 tracts.

1964

County Business Patterns first published.

1990-2010

The 1990 census was the first census where tract maps were made available for the entire U.S. In the late 1990's, Congress and the Census Bureau decided to drop the Long Form and replace it with the American Community Survey. American Community Survey was tested out in 2000-2002 and fully implemented in 2005.

2010-

Census 2010 data is only used for reapportionment. The American Community Survey collects all the socioeconomic data.