“Sand Creek Massacre or Chivington Massacre: November 29, 1864) Surprise attack by U.S. troops on a Cheyenne camp. A force of 1,200 men, mostly Colorado volunteers, under Colonel John M. Chivington attacked several hundred Cheyenne camped on Sand Creek near Fort Lyon in southeastern Colorado territory. The Indians had been conducting peace negotiations with the fort’s commander; when the attack began, they raised a white flag, but the troops continued to attack, massacring over 200 Indians. The slayings led to the Plains Indian wars.”
Excerpted from: Stevens, Mark A., Ed. Merriam-Webster’s Collegiate Encyclopedia. Springfield, Massachusetts: Merriam-Webster, 2000.