The U.S. government will not release personally identifiable information about an individual to any other individual or agency until 72 years after it was collected for the decennial census. This "72-Year Rule" (92 Stat. 915; Public Law 95-416; October 5, 1978) restricts access to decennial census records to all but the individual named on the record or their legal heir.
For More information about the origin of the "72-Year Rule," see the following:
After 72 years, the records are released to the public by the National Archives and Records Administration. In accordance with the 72-Year Rule, the National Archives released the 1930 records in April 2002 and most recently, the 1940 records were released April 2, 2012.
For more information about the origins of the 72-Year Rule, see U.S. National Archives Pieces of History blog, "Census Records: The 72-Year Rule" published on January 20, 2022.
For more information about the availability of census records, download Availability of Census Records About Individuals.
For more information about using census records for genealogical purposes, visit the Genealogy pages.
Records from the 1940 census are still protected by the "72-Year Rule." The National Archives released them on April 2, 2012.