Thomas Mower McDougall subsequently he was appointed Captain, 15 Dec 1875. In 1876 Captain McDougall commanded Company B and accompanied the 7th Cavalry Regiment, under command of Lt. Col. George A. Custer in its fateful departure from Fort Abraham Lincoln to participate in what became known as the Great Sioux War of 1876, which culminated in the Battle of the Little Bighorn, also known as Custer's Last Stand which occurred on June 25–26, 1876. On May 17, 1876, the 7th Cavalry left their base at Fort Abraham Lincoln near present day Mandan, North Dakota to join in a campaign against the Sioux Indians.
George Armstrong Custer A roommate noted, "It was alright with George Custer, whether he knew his lesson or not; he simply did not allow it to trouble him." Under ordinary national conditions, Custer's low class rank would result in an obscure posting, but Custer had the "fortune" to graduate as the Civil War broke out. All officers were needed. Like the other graduates, Custer was commissioned as a second lieutenant; he was assigned to the 2nd U.S. Cavalry Regiment and tasked with drilling volunteers in Washington, D.C. On July 21, 1861, he was with his regiment at the First Battle of Bull Run