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.
Naval Station Great Lakes
On 7 December 1941, Pearl Harbor was attacked by Japan, and around 6,000 sailors were training at Great Lakes. This grew to 68,000 in six months; by September 1942, over 100,000 sailors were training at Great Lakes. The base grew to in the next 10 months. By mid-1943, there were over 700 instructors at the Class A service schools.