United States v. Sioux Nation of Indians their failure to obey an order to return from an off-reservation hunting expedition in the dead of winter when travel was impossible. The consequent military expedition to remove the Sioux from the Black Hills included an attack on their village on the Little Bighorn River led by General Custer. The attack culminated in the victory of Chiefs Sitting Bull and Crazy Horse over the 7th Cavalry Regiment now known as Custer's Last Stand. That victory was short-lived. Those Indians who survived subsequent battles to surrender to the Army were interned on a reservation, and deprived of their weapons and horses,
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