The Battle of Washita River (also called Battle of the Washita or the Washita Massacre) occurred on November 27, 1868 when Lt. Col. George Armstrong Custer’s 7th U.S. Cavalry attacked Black Kettle’s Southern Cheyenne camp on the Washita River (near present-day Cheyenne, Oklahoma). They were the most isolated band of a major winter encampment along the river of numerous Native American tribal bands, totaling thousands of people. But Custer's forces attacked their village because scouts had followed the trail of a party that had raided white settlers and passed through it. Black Kettle and his people had been at peace ... Source: Wikipedia