Historical archaeology deals with the physical evidence of activities by people who also left written records of their history. While written records have been made for thousands of years in some parts of the world, elsewhere the historical period began primarily with European colonizing efforts in the late 15th century, and accompanied the rapid spread of industrial capitalism in the late 18th, 19th and 20th centuries. To a large degree, historical archaeology is the study of the effects of Euro-American colonial and economic expansion on both the colonizers and the colonized.
Although coastal California was visited briefly by seamen in earlier centuries, permanent occupation by foreigners began with Spanish colonization of Alta California in 1769. The Russians also established a colony in Northern California in 1812. Alta California became part of Mexico in 1822, and was in turn seized by the United States in 1846. The Gold Rush followed soon after the American conquest, bring hundreds of thousands of people from all over the world to California. All of these groups and activities produced archaeological sites, many of which have been discovered in California State Parks.