 Increasing impoverishment among the Sioux and continued treaty violations on the part of the United States would soon lead to <unk> . In 1857 a renegade band of Sioux led by war chief <unk> attacked the community of Spirit Lake , Iowa near the Minnesota border killing between 35 and 40 " white " settlers ( the event would be referred to as the Spirit Lake Massacre ) . They went on to attack Springfield , Minnesota ( modern Jackson ) killing seven before being turned back . In 1862 , bands of Sioux launched the Dakota War in which they were defeated . Apart from those killed in the war , 38 Dakota Sioux were killed in a mass execution in <unk> , the largest mass execution in the U.S. history . Hundreds more Sioux and European @-@ Americans were killed in the U.S. government 's subsequent eradication of the Sioux nation in Minnesota and the new Dakota Territory . 
