Grattan massacre near Fort Laramie

Background. Fort Laramie was a significant trading post and military installation at the confluence of the Laramie and North Platte Rivers. The 1851 Treaty of Fort Laramie established relatively peaceful relations, but tensions rose in 1854 due to settler raids. A dispute over a cow killed by a Lakota individual was supposed to be resolved by the Indian agent, but Grattan chose to intervene directly, ignoring treaty stipulations.

The Incident. On August 19, 1854, Grattan led an armed detachment, including two artillery pieces, into a large Lakota camp east of Fort Laramie to arrest High Forehead. The party included a sergeant, corporal, 27 privates, and interpreter Lucien Auguste. After a soldier shot Chief Conquering Bear in the back, the Lakotas returned fire, killing all 29 soldiers and the interpreter.

Historical Interpretation. The U.S. press labeled the event the "Grattan Massacre," though accounts often ignored the soldiers' instigation by failing to leave the dispute to the Indian agent and by shooting Chief Conquering Bear in the back. Historians believe this incident triggered nearly a quarter-century of intermittent warfare on the Great Plains, though other factors contributed to the inevitability of conflict.