California Indigenous communities endured the same kinds of catastrophes that plagued Indigenous people across what became the US. In some ways, the California experience differed from experiences elsewhere, and in other ways it was similar, but in all cases the destructive result was the same. It’s important, therefore, to understand California Indigenous experiences in the larger historical contexts of Catholic missionary activity and US Western expansion.

By the time Spanish missionaries arrived in California in the 1770s, the Indigenous people of the Western Hemisphere, in particular those of Central and South America, had endured the worst effects of colonization—disease and violence—for more than two centuries. The Catholic Church, whose leaders believed that they possessed a divine mandate to save as many souls as possible by whatever means necessary, had perfected the instruments of forced conversion. Wherever Spanish soldiers marched in the Americas, Catholic priests followed close behind, carrying with them all the brutal traditions of the Spanish Inquisition, the sinister and authoritarian institution that terrorized dissenters from Catholicism. In the Catholic missionaries of Spain, therefore, Indigenous people in California met the one group of European Christians who had proved themselves most determined to convert “heathen” souls at any cost.

Catholicism itself didn’t necessarily mean religious terrorism for Indigenous people. When they weren’t brutalized and herded into missions, some Indigenous people converted of their own free will. In Catholic New France (present-day Canada), for instance, French colonization efforts were light, so relations between French settlers and local Indian tribes remained amicable on the whole, at least until British imperialists drove their French rivals out of North America in 1763. Indigenous people in California had the misfortune of encountering the wrong group of Catholics.

The birth of the US in 1776 proved a calamitous development for Indigenous Americans. They now confronted a growing, restless, and acquisitive people bent on Western expansion. Early US presidents, from George Washington to John Quincy Adams, tried to follow a uniform policy of encouraging assimilation while treating Indigenous tribes as domestic-dependent nations and dealing with them by way of treaties. In the 1820s and 30s, however, the new Democratic Party championed a “white man’s democracy.” Presidents Jackson and Van Buren carried out the forced removal of Indigenous tribes from their ancestral homes in the East to new reservations west of the Mississippi River. In the 1840s, a spirit of “Manifest Destiny” gripped the nation as thousands of Americans pushed westward into the Plains, Rocky Mountains, and Pacific Northwest, while others moved southwest toward Mexico. This mass migration triggered the Mexican American War of 1846-1848, which ended in a US victory and the acquisition of nearly all the present-day American Southwest, including California.

Meanwhile, Indigenous people in California faced a new and advancing threat: the 1849 Gold Rush. The discovery of gold at Sutter’s Mill, California, in 1848 led to a mad scramble for quick riches. Prospectors and squatters became land thieves as they descended on California in unprecedented numbers. The demographic impact of this gold rush was so staggering that California achieved statehood in 1850, a mere two years after the US acquired California as part of the treaty that ended the Mexican American War.

The sheer suddenness with which Americans overran California in the 1840s and 1850s made the experience unique for Indigenous people in California. Because of the Mexican American War, US expansion didn’t proceed linearly from East to West. California entered the Union before Kansas, Nebraska, and nearly every other state west of the Mississippi. From Indigenous perspectives, this was an invasion on a much larger scale than that of the 18th-century Spanish missionaries. Thus, Indigenous people of Northern California who had managed to evade the Spaniards now faced a much more aggressive group of settlers who were determined to stay. For Indigenous people who somehow survived the Spanish missions, it meant a new sovereign power whose leaders and institutions had shown little regard for Indigenous land rights.