The California Genocide was the extermination of the Native American peoples of California by the US Army, the California State Militia, and Mexican, Spanish, and other European settlers from 1846 to 1871 which resulted in the decline of the Native population of California from 150,000 in 1848 to 30,000 in 1870 and 16,000 in 1900.
Before the Spanish colonization of Alta California, around 300,000 Natives inhabited the region, and the native tribes adapted to particular areas and territories and were apparently peaceful. The Natives followed a hunter-gatherer lifestyle, subsisting on rabbits, deer, fish, fruit, roots, and acorns. Led by Gaspar de Portola, the Spanish arrived in the region in 1769 and established 21 Roman Catholic missions to convert the Natives to Christianity, the first mission being San Diego. The Spanish also built several military outposts to house the soldiers sent to protect the missionaries. The Spanish and their Mexican descendants imported diseases and disrupted the Natives' ways of life, killing around 33% of their population, and the Spanish and Mexicans also implemented virtual slavery on their Native missions.
After the Mexican-American War and the Treaty of Guadalupe Hidalgo, the United States acquired the Mexican Cession (including Alta California) from the Mexican government, and the California Gold Rush of 1849-1855 led to a sudden influx of tens of thousands of settlers and prospectors to the state. California state and federal authorities incited, aided, and financed miners, settlers, ranchers, and volunteer militias to enslave, kidnap, murder, and exterminate a major proportion of displaced Native Americans; in 1850, the state passed an act allowing for whites to enslave Native Americans as forced laborers, leading to slave raids on Native villages. The Native Americans were driven from their homes and were starved out, acquiring the pejorative nickname "Diggers" for digging up roots to eat. Around 27,000 Native Americans would be enslaved (7,000 of them children), and between 4,500 and 100,000 Natives were killed by settlers from 1849 to 1870. More than 370 massacres were recorded during the California Indian Wars between the US Army, state militias, and the native populations. During the first two years of the Gold Rush alone, well-armed death squads and individual miners were estimated by a Sonoma State University professor to have killed around 100,000 Natives. The last major massacre was the Kingsley Cave massacre of 1871. In June 2019, Governor Gavin Newsom apologized for the California Genocide and supported the creation of a Truth and Healing Council.