Some 127,000 people of Japanese descent lived in the United States at the time of the Japanese attack on Pearl Harbor, Hawaii, on December 7, 1941. Most of them, some 112,000, lived on the West Coast. Two-thirds were native–born U.S. citizens and the remainder were immigrants who held no U.S. citizenship because of existing immigration laws preventing Asian immigrants from acquiring citizenship.

Following Pearl Harbor, public fears of Japanese espionage and sabotage dramatically rose. On February 19, 1942, President Franklin D. Roosevelt (1882–1945; served 1933–45) signed the Japanese American removal order, Executive Order 9066, with the War Relocation Authority (WRA) in charge. Japanese Americans had to register at WRA control stations by the end of March, where each family was issued a number and assigned a time to report for removal. Since they could only bring what they could carry, they had to hastily sell their businesses and...