Sand Creek massacre
In 1865, the Joint Committee on the Conduct of the War investigated the Sand Creek massacre and concluded the following: "the truth is that he [Col. Chivington] surprised and murdered, in cold blood, the unsuspecting men, women, and children on Sand creek, who had every reason to believe they were under the protection of the United States authorities, and then returned to Denver and boasted of the brave deed he and the men under his command had performed."