5. The Second War Powers Act of 1942 enabled the Census Bureau to support internment
The information collected by the Census conducted every decade was protected by law from being divulged for the purpose of linking it to specific persons. In 1942 the Second War Powers Act was passed by Congress and signed into law by President Roosevelt, which removed the individual protections from the census data, enabling the Bureau to support efforts to identify Americans of Japanese descent, and where they lived and worked. For more than seventy years the Department of Commerce, which oversaw the Census Bureau and the data which it collected, denied that census information was provided to other government agencies involved in the internment process. In the early 21st century government records were revealed that proved census data was requested and received by the Department of the Treasury (which ran the Secret Service), and other government agencies, including the FBI.
Census information was provided which covered the Japanese communities in larger cities, as well as the location of descendants living separately, children away at school, and other information about activities. Information regarding the families and relatives of specific individuals was requested by law enforcement agencies, the Secret Service, the FBI, and other agencies of the government, which was provided as the change in the law required. After the war ended the federal government restored the protections which ensured that census data remained confidential. The protections were restored in 1947. The use of census data allowed the government to more closely monitor the activities of multiple generations of Japanese families as well as those of other races in cases where Japanese descendants had married into them.