In the nineteenth century, the county witnessed many of the most serious atrocities in the extermination of the Californian Native American tribes who originally lived in the area, like the Yuki, the Pomo and the Wintun. The systematical occupation of their lands, the reduction of many of their members into slavery and the raids against their settlements led to the Mendocino War in 1859, where hundreds of Indians were killed. Later, the segregation continued well into the 20th century.