IPUMS USA
Collects, preserves and harmonizes U.S. census microdata and provides easy access to this data with enhanced documentation. Data includes decennial censuses from 1790 to 2010 and American Community Surveys (ACS) from 2000 to the present.
The Integrated Public Use Microdata Series (IPUMS-USA) consists of samples of the American population drawn from federal censuses and from the American Community Surveys of 2000-2012. These samples, which draw on every surviving census from 1850-2000, and the 2000-2012 ACS samples, collectively constitute our richest source of quantitative information on long-term changes in the American population.