On February 19, 1942 President Roosevelt signed Executive Order 9066 providing broad powers for the War Department to create exclusion zones and to initiate an evacuation program for the Western Defense Command (WDC). Under the leadership of General John Dewitt of the WDC, the Civil Affairs Division (CAD) and the Wartime Civil Control Administration (WCCA) were created in order to provide for the transition of voluntary evacuees, enemy aliens and United States citizens alike, from exclusion areas to other parts of the country. The failure of the voluntary evacuation plan led President Roosevelt to issue Executive Order 9102, which established the civilian run War Relocation Authority (WRA). The WRA was mandated to institute enforced evacuations. Due to the recalcitrance of states on the interior of the country to accept the Japanese evacuees or to provide for their safety, the WRA also constructed internment centers in order to house the evacuees. Between 1942-1945 the WRA, the WCCA, the CAD and the Office of the Commanding General of the Western Defense Command segregated and housed approximately 110,000 Japanese-American men, women and children.

Though the initial exclusion plan put forth by General Dewitt included both German and Italian citizens, the Japanese Americans bore the brunt of Executive Order 9066.