California during World War II was a major contributor to the World War II effort. California's long Pacific Ocean coastline provided the support needed for the Pacific War. California also supported the war in Europe. After the Japanese attack on Pearl Harbor, Hawaii, on December 7, 1941, most of California's manufacturing was shifted to the war effort.
California aviation companies designed many of the greatest combat aircraft of the era, and bustling armies of women and men helped quickly churn them out by the thousands. An astounding 41 percent of all US warplanes came from California drawing boards during the war. These planes saw combat service everywhere--from the deserts of North Africa to the tundra of Alaska. Southern California planes were the first to bomb Japan. They turned the tide at the Battle of Midway and dropped paratroopers behind enemy lines on D-Day. They flew tons of fuel, ammunition, and supplies over the treacherous Himalayan Mountains relentlessly hounded enemy submarines and ships, and helped smash Nazi Germany's war-making industry with "thousand plane raids."