The Sand Creek Massacre of 1864, in which Colonel John Chivington’s Colorado volunteers attacked a peaceful Cheyenne and Arapaho encampment and killed approximately 150-200 people, the majority of them women, children, and elderly, had produced a significant political and legal controversy that shaped subsequent Army operations.

Mackenzie at Palo Duro was operating in the shadow of Sand Creek.

His decision to burn the camps and destroy the horses rather than pursue and engage the fleeing families was, in part, a recognition that the political and legal consequences of a mass killing of non-combatants would be different from the consequences of material destruction alone.

The result was a campaign that was, by the standards of the 1870s, “humane” in the specific sense of not producing mass civilian casualties, and devastating in the specific sense of eliminating the material conditions for survival.

The families who survived the September 28 attack faced a winter that the destruction of their supplies made far more dangerous than it would otherwise have been.