The Wounded Knee Massacre was a battle between Indians and the U.S. Army on December 29, 1890. The U.S. Cavalry were ordered to remove some Lakota Sioux from their reservation in South Dakota to another reservation in Nebraska. The attempt to disarm the Indians turned fatal when a dispute over one tribesman's rifle turned into a major exchange of gunfire.
In the end, over 150 Native Americans, including women and children, were killed, along with 25 U.S. soldiers, most of whom were killed by friendly fire.
The battle ended the Indian conquest as the very few Indians alive were forced to returned peacefully to their reservations.
The battle is an iconic signpost of Native American history, usually brought up by liberals—they always call it a "massacre"—to attack national policy and seek additional privileges for Native Americans today.