Sitting Bull as hostiles those Sioux and others living off the reservation, Native Americans gathered at Sitting Bull's camp. He took an active role in encouraging this "unity camp". He sent scouts to the reservations to recruit warriors, and told the Hunkpapa to share supplies with those Native Americans who joined them. An example of his generosity was Sitting Bull's taking care of Wooden Leg's Northern Cheyenne tribe. They had been impoverished by Captain Reynold's March 17, 1876 attack and fled to Sitting Bull's camp for safety. Over the course of the first half of 1876, Sitting Bull's camp continually expanded, as
Sitting Bull natives joined him for safety in numbers. His leadership had attracted warriors and families, creating an extensive village estimated at more than 10,000 people. Lt. Col. Custer came across this large camp on June 25, 1876. Sitting Bull did not take a direct military role in the ensuing battle; instead he acted as a spiritual leader. A week prior to the attack, he had performed the Sun Dance, in which he fasted and sacrificed over 100 pieces of flesh from his arms. Custer's 7th Cavalry advance party attacked Cheyenne and Lakota tribes at their camp on the Little Big Horn