The Dakota War of 1862, also known as the U.S.-Dakota War of 1862, the Sioux Uprising, the Dakota Uprising, the Sioux Outbreak of 1862, the Dakota Conflict, or Little Crow's War, was an armed conflict between the United States and several eastern bands of Dakota collectively known as the Santee Sioux. It began on August 18, 1862, when the Dakota, who were facing starvation and displacement, attacked the Lower Sioux Agency and white settlements along the Minnesota River valley in southwest Minnesota. The war lasted for five weeks and resulted in the deaths of hundreds of settlers and the displacement of thousands more. In the aftermath, the Dakota people were exiled from their homelands, forcibly sent to reservations in the Dakotas and Nebraska, and the State of Minnesota confiscated and sold all their remaining land in the state. Thirty-eight Dakota men were subsequently hanged for crimes committed during the conflict in the largest mass execution in US history.
All four bands of eastern Dakota had been pressured into ceding large tracts of land to the United States in a series of treaties and were reluctantly moved to a reservation strip twenty miles wide, centered on the Minnesota River. There, they were encouraged by U.S. Indian agents to become farmers rather than continue their hunting traditions. A crop failure in 1861, followed by a harsh winter along with poor hunting due to depletion of wild game, led to starvation and severe hardship for the eastern Dakota. In the summer of 1862, tensions between the eastern Dakota, the traders, and the Indian agents reached a breaking point. On August 17, 1862, four young Dakota men killed five white settlers in Acton, Minnesota, after a disagreement. That night, a faction led by Chief Little Crow decided to attack the Lower Sioux Agency the next morning in an effort to drive all settlers out of the Minnesota River valley. The demands of the Civil War slowed the U.S. government response, but on September 23, 1862, an army of volunteer infantry, artillery and citizen militia assembled by Governor Alexander Ramsey and led by Colonel Henry Hastings Sibley finally defeated Little Crow at the Battle of Wood Lake. Little Crow and a group of 150 to 250 followers fled to the northern plains of Dakota Territory and Canada.