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.
7th Cavalry Regiment September 1866 at Fort Riley, Kansas, as part of an expansion of the regular army following the demobilization of the wartime volunteer and draft forces. From 1866 through 1871, the regiment was posted to Fort Riley and fought in the American Indian Wars. In the Battle of the Washita in 1868, the regiment sustained 22 losses, while inflicting more that 150 deaths on a Cheyenne encampment, mostly women and children . This attack was led by George Armstrong Custer, who later led the 7th Cavalry to the most calamitous defeat of U.S. forces in the Indian Wars. Typical of post-Civil