From a U.S. Census Announcement:
We are pleased to announce the release of the 2010 American Community Survey (ACS) 1-Year Public Use Microdata Sample (PUMS) files. PUMS files from the ACS show the full range of population and housing unit responses collected on individual ACS questionnaires. These files enable users to design tabulations that aggregate responses differently than the published data products.
The PUMS files contain records for a subsample of ACS housing units and group quarters persons. As required by federal law, the confidentiality of ACS respondents is protected through a variety of steps to disguise or suppress original data while making sure the results are still useful. In addition to modifying the individual records, respondents’ confidentiality is protected because only large geographic areas are identified in the PUMS. To read more about how the PUMS files are created, browse code lists, and look-up subjects in the PUMS, please visit the PUMS Documentation Page.
The PUMS data is accessible now via the FTP site. Links can be found on our PUMS Data Page.
On October 27, 2011 the data will also be accessible via American FactFinder.
See Also: Poverty: 2009 and 2010