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.
2nd West Virginia Volunteer Cavalry Regiment and a new CompanyG consisted of men from CompanyM. The new regiment commander was Lieutenant Colonel James Allen. His second-in-command was Major Edwin S. Morgan. General Sheridan now led an 8,000-man force, and it consisted of two cavalry divisions. General Wesley Merritt was Sheridan's cavalry commander. General Thomas Devin led the 1st Division, and the 3rd Division was commanded by George Armstrong Custer, who was now a general. The 2nd West Virginia Cavalry became part of the 3rd Brigade, 3rd Division Cavalry Corps. The brigade consisted of the 1st, 2nd, and 3rd West Virginia Cavalry regiments, and was commanded by