Lean Bear and the other Cheyenne chiefs came away from their meeting with President Lincoln in 1862 feeling good about the outcome. They even took a detour to visit New York at the request of P. T. Barnham and visited his museum.
But in less than two years, in the spring of 1864, despite promises from Lincoln to keep the peace, things took a tragic turn. Lean Bear with his wife and tribe were camped near Ash Creek in Kansas on a buffalo hunt when troops from the Colorado Militia approached them. Unarmed, Chief Lean Bear grabbed his medal and letter from Lincoln proclaiming him a friend and peacekeeper and went out to meet the troops. Unbeknownst to him, Lieutenant George Eayre, who was in command, was acting under orders from Colonel John M. Chivington to kill all Indians on sight.