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.
Bury My Heart at Wounded Knee Hills, angering the Lakota and Dakota living there. A peace council in 1875 tried to arrange for the US government to either purchase the mineral rights or outright ownership of the Black Hills, but both proposals were rejected by the Sioux. In 1876, a series of battles occur between the Sioux and US troops which initially ends when the Sioux defeat General Custer and his troops at the Battle of Little Bighorn on June 25. The humiliated US Army sends a peace council to sign a treaty that forces the Sioux out of the Black Hills to the Missouri River.