California during World War II

California was a major contributor to the World War II effort. After the Japanese attack on Pearl Harbor, the majority of manufacturing in California shifted to accommodate the war effort, causing the state to become a major ship builder and aircraft manufacturer, along with expanding oil and mineral production. Agriculture, ranches, and farms were used to feed the troops around the world.

Existing military installations were enlarged and many new ones were built to keep up with the demand. The state trained many of the troops before their oversea deployment, causing the population to grow significantly. Along with the servicemen stationed at the new military bases and training facilities, there was a mass influx of people from around the U.S. coming to work in the growing defense industries. Over 800,000 Californians served in the United States Armed Forces. With all the new economic activity, California was lifted out of the Great Depression. Over 500,000 people moved there from other states to work in the growing economy.

California's long coastline along the Pacific Ocean provided support needed for the Pacific War, but was also seen as a vulnerability, as an attack seemed likely. Because of growing anxiety surrounding potential attacks, the state was used for the temporary and permanent internment camps for Japanese Americans.