Under pressure from the European Americans, in the late 19th century the Nez Perce split into two groups: one side accepted the coerced relocation to a reservation and the other refused to give up their fertile land in Idaho and Oregon. Those willing to go to a reservation made a treaty in 1877. The flight of the non-treaty Nez Perce began on June 15, 1877, with Chief Joseph, Looking Glass, White Bird, Ollokot, Lean Elk (Poker Joe) and Toohoolhoolzote leading 2,900 men, women and children in an attempt to reach a peaceful sanctuary. They intended to seek shelter with their allies the Crow but, upon the Crow's refusal to offer help, the Nez Perce tried to reach the camp in Canada of Lakota Chief Sitting Bull. He had migrated there instead of surrendering after the Indian victory at the Battle of the Little Bighorn.