On December 29, 1890, hundreds of U.S. troops surrounded a Lakota camp and opened fire, killing more than 300 Lakota women, men, and children in a violent massacre.

In December 1890, Sioux Chief Sitting Bull—who led his people during years of resistance to U.S. government policies—was killed by Indian Agency Police on the Standing Rock Indian Reservation as authorities attempted to arrest him for his involvement in the Ghost Dance movement.

In the late 19th century, the U.S. Government began forcefully relocating Native Americans onto reservations, where they were dependent on the government for food and clothing. In response, some Native American people embraced a religion called Ghost Dance, which promoted the belief that Native Americans would become bulletproof and return to their freedom following a great apocalypse. The Ghost Dance performance and religion frightened the U.S. federal government, and sensationalist newspapers across the country stoked fears about an uprising by Native Americans.

Shortly after Sitting Bull’s killing, the Sioux surrendered and were marched to the Pine Ridge Reservation in South Dakota. On the morning of December 29, 1890, 500 troops of the U.S. 7th Calvary Regiment surrounded a group of Lakota Sioux where they had made camp at Wounded Knee Creek. The troops entered the camp to disarm the Lakota. During a brief scuffle between a soldier and a Lakota man who refused to surrender his weapon, the rifle fired, alarming the rest of the troops. The troops began firing on the Lakota, many of whom tried to recapture weapons or flee the assault. The attack lasted for more than an hour and left more than 300 Lakota dead; over half of those killed were women, children, and elderly tribal members, and most of the dead were unarmed.