The Dakota War of 1862 (also known as the Sioux Uprising, Sioux Outbreak of 1862, the Dakota Conflict, the U.S.–Dakota War of 1862, or Little Crow's War) was an armed conflict between the United States and several bands of the eastern Sioux or Dakota which began on August 17, 1862, along the Minnesota River in southwest Minnesota and ended with a mass execution of thirty-eight Dakota on December 26, 1862, in Mankato, Minnesota.
On August 17, five American settlers were killed by four Dakota on a hunting expedition. That night, a council of Dakota decided to attack settlements throughout the Minnesota River valley in an effort to drive whites out of the area. Continued battles between the Dakota against settlers and later, the United States Army, ended with the surrender of most of the Dakota forces. There has never been an official report on the number of settlers killed, but estimates range from 400 to 800.
By late December, more than a thousand Dakota were interned in jails in Minnesota, and 38 Dakota were hanged in the largest one-day execution in American history on December 26. In April 1863, the rest of the Dakota were expelled from Minnesota to Nebraska and South Dakota, and their reservations were abolished by the United States Congress.