evacuation: executive order 9066
By December 1941 over 126,000 individuals of Japanese ancestry resided on the United States mainland. Many lived along the West Coast. Approximately seventy percent were Nisei, the first American-born generation. Their parents, Issei or immigrating generation, left Japan for a better life but encountered many obstacles in the United States. Intense discrimination from nativists limited employment opportunities and successfully prevented the Issei from becoming U.S. citizens. In 1922, the U.S. Supreme Court in the case of Ozawa v. United States upheld legislation that declared the Issei "aliens ineligible to citizenship." Emigration from Japan ended with the 1924 Johnson-Reed Act that established quotas for every national group and barred the entrance of aliens ineligible to citizenship.
On 19 February 1942, in the wake of the Japanese attack on Pearl Harbor, President Franklin D. Roosevelt issued Executive Order 9066, enabling the U.S. Army to forcibly remove any and all persons from areas of strategic importance. Lieutenant General John L. DeWitt, head of the Western Defense Command, ordered Japanese Americans to be evacuated from coastal areas in Washington, Oregon, California, and Arizona.