When the USA acquired South Dakota with the 1803 Louisiana Purchase, the region was the domain of the Sioux and a few fur trappers. It wasn’t until the 1850s that the rich Dakota soil attracted the interest of settlers.
The 1868 Fort Laramie Treaty between the USA and the Sioux promised the Sioux a 60-million-acre reservation that stretched from the Missouri River in the east to the Bighorn Mountains in the west. The treaty was broken in 1874 after Lt Col George Custer led an expedition into the Black Hills in search of gold. Unfortunately for the Sioux, he found it.
Miners and settlers soon streamed in illegally and the Sioux retaliated in the biggest of the Indian Wars. The Battle of Little Bighorn in 1876, in which the great Crazy Horse defeated Custer and killed every last soldier, was the Plains Indians’ last major victory over the invaders. Faced with overwhelming force, the tribes split up. Sitting Bull fled to Canada, Crazy Horse turned in his gun in 1877, and the railroads and settlers continued the march west. The final decimation of Sioux resistance came at Wounded Knee in 1890. Much later, in 1973, Oglala Sioux loyal to the American Indian Movement and opposed to their tribal leaders occupied Wounded Knee and kept federal officers at bay for 71 days.