After the Civil War, Custer remained a major general in the United States Volunteers until they were mustered out in February 1866. He reverted to his permanent rank of captain and was appointed a lieutenant colonel in the 7th Cavalry Regiment in July 1866. He was dispatched to the west in 1867 to fight in the American Indian Wars. On June 25, 1876, while leading the 7th Cavalry Regiment at the Battle of the Little Bighorn in Montana Territory against a coalition of Native American tribes, he and all of his regiment—which included two of his brothers—were killed. The battle is popularly known in American history as "Custer's Last Stand." Custer and his regiment were defeated so decisively at the Little Bighorn that it has overshadowed all of his prior achievements

More Info: en.wikipedia.org