Roosevelt authorized Executive Order 9066, issued two months after Imperial Japan's attack on Pearl Harbor. The order allowed regional military commanders to designate "military areas" from which "any or all persons may be excluded." Although the executive order did not mention Japanese Americans, this authority was used to declare that all people of Japanese ancestry were required to leave Alaska and the military exclusion zones from all of California and parts of Oregon, Washington, and Arizona, with the exception of those inmates who were being held in government camps. The detainees were not only people of Japanese ancestry, they also included a relatively small number—though still totaling well over ten thousand—of people of German and Italian ancestry as well as Germans who were expelled from Latin America and deported to the U.S. Approximately 5,000 Japanese Americans relocated outside the exclusion zone before March 1942, while some 5,500 community leaders had been arrested immediately after the Pearl Harbor attack and thus were already in custody.
