The Great Sioux War of 1876, also known as the Black Hills War, was a series of battles and negotiations that occurred in 1876 and 1877 in an alliance of Lakota Sioux and Northern Cheyenne against the United States. The cause of the war was the desire of the US government to obtain ownership of the Black Hills. Gold had been discovered in the Black Hills, settlers began to encroach onto Native American lands, and the Sioux and the Cheyenne refused to cede ownership. Traditionally, American military and historians place the Lakota at the center of the story, especially because of their numbers, but some Native Americans believe the Cheyenne were the primary target of the American campaign.

The Lakota are a Native American people. Also known as the Teton Sioux, they are one of the three prominent subcultures of the Sioux people, with the Eastern Dakota (Santee) and Western Dakota (Wičhíyena). Their current lands are in North and South Dakota. They speak Lakȟótiyapi—the Lakota language, the westernmost of three closely related languages that belong to the Siouan language family.