On June 25, 1876, Native American forces led by Crazy Horse
and Sitting Bull defeated the U.S. Army troops of Lt. Col. George
Armstrong Custer in the Battle of the Little Bighorn near southern Montana’s Little Bighorn River.

Crazy Horse and Sitting Bull, Lakota Sioux leaders, strongly
resisted the mid-19th-century efforts of the U.S. government
to confine their people to reservations. In 1875, after gold was
discovered in South Dakota’s Black Hills, the U.S. Army ignored
previous treaty agreements and invaded the region. This betrayal
led many Sioux and Cheyenne tribesmen to leave their reservations
and join Sitting Bull and Crazy Horse in Montana.