At the Battle of the Little Bighorn in Montana Territory during the Black Hills War, he was acting as temporary commander of L Company, whose commander was on detached service as aide to General Philip H. Sheridan, and killed along with most of the company. Evidence at the hill where he died, later known as Calhoun Hill, showed that he and his men fought fiercely before they were killed. He and his second in command, Lt. John Crittenden, were found within feet of each other and their men initially had been deployed in a defensive perimeter on the hill. His remains were initially buried on the battlefield, but were reinterred in Fort Leavenworth National Cemetery in Fort Leavenworth, Kansas, in 1877. A marble slab on the Little Bighorn battlefield marks the place where his body was discovered and initially buried.