Sitting Bull's persistence in not yielding to the U.S. government's attempts to move his reservation unified the Sioux, Cheyenne, and Arapaho Indians into a force of nearly 4,000 men and boys in 1876. In that year he led a sun dance where he told the Indians to change their way of fighting. Rather than merely to prove their bravery, they needed to fight to kill. He had a vision the pervious year of the coming of many soldiers and their "falling right and left into our camp." On June 25, 1876, the apparition came true in the form of Gen. George Custer and his soldiers at Little Bighorn. After that battle, Sitting Bull and his followers were driven into Canada. He was killed during an attempt by government agents to separate him from dancers at a Ghost Dance agitation.