Thomas Custer in the Yellowstone Expedition of 1873, where he fought in the Battle of Honsinger Bluff, and the Black Hills Expedition of 1874. Custer was appointed captain in 1875 and given command of Company C of the 7th Cavalry. In 1874, at the trading post at Standing Rock Agency, Custer participated in the arrest of chief Rain-in-the-Face (Lakota), suspected in the 1873 murder of Dr. John Honsinger. During the 1876 Little Bighorn campaign of the Black Hills War, he served as aide-de-camp to his older brother Lt. Col. George A. Custer and died with his brother on June 25, 1876. Lt.
Battle of the Little Bighorn size of cavalry companies to 100 enlisted men on July 24. The committee temporarily lifted the ceiling on the size of the Army by 2,500 on August 15. As a result of the defeat in June 1876, Congress responded by attaching what the Sioux call the "sell or starve" rider () to the Indian Appropriations Act of 1876 (enacted August 15, 1876), which cut off all rations for the Sioux until they terminated hostilities and ceded the Black Hills to the United States. The Agreement of 1877 (, enacted February 28, 1877) officially took away Sioux land and permanently established