History of Hawaii
Pearl Harbor was surprisingly attacked on December 7, 1941 by the Imperial Japanese Navy, killing 2,403 people and sinking the main American battleship fleet. Fortuitously, the four Pacific aircraft carriers were not in port and escaped damage. Hawaii was put under martial law until 1945. Unlike the West Coast of the United States in which 100,000 ethnic Japanese citizens were interned, the Japanese American population in Hawaii completely avoided such similar fate, though hundreds of pro-Japan leaders were arrested. Pearl Harbor was the U.S.' main forward base for the Pacific War. The Japanese tried to invade in summer 1942 but were defeated at the Battle of Midway. Hundreds of thousands of American soldiers, sailors, Marines, and airmen passed through on their way to the fighting.
Consequences of the attack on Pearl Harbor
The day after the attack, President Franklin D. Roosevelt addressed a joint session of the 77th United States Congress, calling December 7 "a date which will live in infamy". Within an hour of Roosevelt's speech, Congress declared war on the Empire of Japan amid outrage at the attack, the deaths of thousands of Americans, and the late delivery of the note from the Japanese government breaking off relations with the U.S. government. Pacifist Representative Jeannette Rankin, a Republican from Montana, cast the only dissenting vote. Roosevelt signed the declaration of war later the same day. Continuing to intensify its military mobilization, the U.S. government finished converting to a war economy, a process begun by provision of weapons and supplies to the Soviet Union and the British Empire. Japanese Americans from the West Coast were sent to internment camps for the duration of the war.