The population of California grew an unprecedented amount during the 20th century. In the 1920s and 1930s the oil, agriculture and entertainment industries succeeded in attracting millions of people to Southern California, which subsequently overtook Norther California as the driving force of the economy in the thriving state.
During World War II, California’s emerging aerospace and supplying industries again brought millions of workers from a variety of geographical and cultural background to the state, and immigration rates continued to increase after the war’s end. In the 20th century, California’s millions of Native Americans, African Americans and Hispanic Americans strove for economic security, political equality and social change, met by friction due to local racial tension.
In 1962, California overtook New York as the nation’s most populous state. In the 21st century, California has the 5th largest economy in the world and has a population of 34 million people. Housing, transportation, healthcare and social service infrastructure has failed in keeping up with the state’s unmanageable growth, and as a result cities began to suffer from poverty, pollution, and racial strife.
Paddison, Joshua. "1921-present: Modern California” Migration, Technology, Cities." Calisphere. http://www.calisphere.universityofcalifornia.edu/calcultures/eras/era6.html (accessed December 4, 2012).