The Founding of South Dakota: From Dakota Territory to Statehood

The Dakota Territory was created by the U.S. Congress in 1861 during the Civil War. In 1889, on the centennial of George Washington's inauguration, the territory was divided. The southern portion became the State of South Dakota, admitted to the Union on November 2, 1889, as the 40th state—simultaneously with North Dakota, Montana, and Washington.

South Dakota had been proposed for statehood four times before finally achieving it.