On February 19, 1942, President Franklin Roosevelt signed Executive Order 9066, authorizing General John L. DeWitt, head of the Western Defense Command, to remove Japanese residents from sensitive military areas. In March, DeWitt issued the first of a series of Civilian Exclusion Orders, requiring all persons of Japanese ancestry, regardless of citizenship, to evacuate the western portions of Washington, Oregon, and California, and the southern portion of Arizona, an area that DeWitt had designated Military Area Number One.

Japanese Americans were at first encouraged to relocate on their own. Three thousand Japanese residents, many of whom had relatives and friends in the midwest and on the East Coast, took advantage of the opportunity. The majority of Japanese, however, had lived their entire lives on the West Coast and had little prospect of being able to settle elsewhere. By the end of March, more than 100,000 Japanese remained on the Pacific...