In 1941, nearly 113,000 people of Japanese ancestry, two-thirds of them American citizens, were living on the West Coast, in California, Washington, and Oregon. On December 7, Japan attacked the United States naval base at Pearl Harbor, and the United States declared war on Japan. Two months later, President Franklin D. Roosevelt signed Executive Order No. 9066 empowering the U.S. Army to designate areas from which people could be excluded. Although the Executive Order did not identify who was to be excluded, the Army enforced its provisions only against Japanese Americans. No person of Japanese ancestry living in the United States was ever convicted of any serious act of espionage or sabotage during the war, yet the entire West Coast population of people of Japanese descent was forcibly removed from their homes and placed in relocation centers, many for the duration of the war.