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.
5th Cavalry Regiment Henry Thomas. The regiment was rebuilt with new officers and recruits loyal to the Union and was assigned to the Army of the Potomac under the command of General George McClellan. On 21 July 1861, the regiment participated in its first battle of the American Civil War, the First Battle of Bull Run; it was the last action in which they would be called the "2nd Cavalry." In the summer of 1861, all regular mounted regiments were re-designated as "cavalry", and being last in seniority among the existing regiments, the regiment was re-designated as the 5th United States Cavalry. During