During World War II, the Los Angeles region underwent rapid industrial growth as Kaiser Steel opened a giant mill in Fontana, and the aircraft giants--North American Aviation, Lockheed, Douglas, and Hughes--expanded with war contracts. The war economy's demographic and ethnic dimensions included women and African Americans entering factory work and troops streaming through Union Station to San Pedro for embarkation. The Zoot Suit Riots defined the tensions between servicemen and the Mexican American community, and the internment of Japanese Americans led to the eventual disappearance of established neighborhoods. The war inspired home front efforts by local civic and academic institutions, by the entertainment industry, and by emigres from Nazi Germany. It led to the training of civilian corps, rationing, and vigilance for enemy activities. American participation in World War II from 1941 to 1945 energized the region's growing industrial infrastructure and spurred postwar economic and housing development."