In fact, information from the 1940 Census was secretly used in one of the worst violations of constitutional rights in U.S. history: the internment of Japanese Americans during World War II.
In papers presented in
2000 and
2007, historian Margo J. Anderson of the University of Wisconsin at Milwaukee and statistician William Seltzer of Fordham University found evidence that census officials cooperated with the government, providing data to target Japanese Americans.
...
In 2000, Anderson and Seltzer found documents that showed officials with the Census Bureau had provided block-level information of where those of Japanese ancestry were living in California, Arizona, Wyoming, Colorado, Utah, Idaho and Arkansas.
The revelations prompted Kenneth Prewitt, then director of the U.S. Census Bureau, to issue a public apology. Prewitt wrote: “The historical record is clear that senior Census Bureau staff proactively cooperated with the internment, and that census tabulations were directly implicated in the denial of civil rights to citizens of the United States who happened also to be of Japanese ancestry."
Anderson and Seltzer, however, weren’t finished. They suspected that despite the bureau’s denials, it had also released “microdata” — information about individuals, including names and addresses.
In 2007, they found proof, uncovering documents that showed Census Bureau officials provided names and addresses of individuals of Japanese ancestry in Washington, D.C.