The Camp Grant massacre takes place in Arizona Territory.

The Camp Grant massacre took place on April 30, 1871, near Camp Grant in what is now Arizona. It involved a coordinated attack by a group of Anglo-American settlers, Mexican Americans, and Tohono O’odham allies on a camp of Apache people—primarily women, children, and elderly individuals—who had been living near the U.S. Army post under an uneasy peace arrangement. These Apaches, often identified as Aravaipa and Pinal groups, had been trading with the soldiers and settlers and were not engaged in active hostilities at the time. Despite this, tensions in the region remained high due to ongoing conflicts between settlers and various Apache bands across the Southwest.

In the early morning hours, the attackers descended on the Apache encampment, killing over 140 people, the vast majority of whom were non-combatants. Children who survived were taken captive and later sold into servitude in Mexico. The brutality of the massacre shocked some observers, particularly in the eastern United States, where reports emphasized the indiscriminate nature of the violence. However, many local settlers defended the attack, arguing that it was a necessary measure in the broader context of frontier warfare and ongoing raids attributed—fairly or not—to Apache groups.

The aftermath of the massacre highlighted deep divisions in American society regarding Indigenous policy and frontier justice. A trial was held for the leaders of the attack, including William S. Oury, but all defendants were acquitted by a local jury in Tucson after a brief deliberation. The verdict underscored the prevailing attitudes of the time, where violence against Native Americans was often tolerated or justified by settler communities. Today, the Camp Grant massacre is remembered as a tragic example of the consequences of fear, prejudice, and the breakdown of diplomacy during the westward expansion of the United States.