4th Cavalry Regiment (United States) companies of the 4th Cavalry to Fort Clark. This time Mackenzie led a larger and more extensive expedition into Mexico, restored a system of patrols, and reestablished peace in the devastated region of South Texas. Outside Texas, Mackenzie and the 4th Cavalry administered and controlled the Kiowa-Comanche and the Cheyenne-Arapaho reservations for several years, and, after the defeat of George Armstrong Custer's command at the Battle of Little Bighorn in June 1876, forced Crazy Horse and his band of Sioux and the Northern Cheyennes to surrender. In the autumn of 1879, Mackenzie with six companies of the 4th Cavalry subdued
George Armstrong Custer during the Manassas Campaign, where Army commander Winfield Scott detailed him to carry messages to Major General Irvin McDowell. After the battle, Custer continued participating in the defenses of Washington D.C. until October, when he became ill. He was absent from his unit until February 1862. In March, he participated with the 2nd Cavalry in the Peninsula Campaign (March to August) in Virginia until April 4. On April 5, Custer served in the 5th Cavalry Regiment and participated in the Siege of Yorktown, from April 5 to May 4 and was aide to Major General George B. McClellan; McClellan was