About South Dakota

South Dakota was part of the territory acquired by the United States through the Louisiana Purchase. Its boundaries and territorial government changed several times before statehood.

• 1803The United States completed the Louisiana Purchase from France.
• 1861Dakota Territory was organized, originally including present-day North Dakota, South Dakota, Montana, Wyoming, and part of Nebraska.
• 1868Dakota Territory was reduced to the area now occupied by North Dakota and South Dakota.
• 1889The Enabling Act divided Dakota Territory, and South Dakota entered the Union as a state.

Today, South Dakota lies in the heartland of the United States and measures approximately 370 miles east to west by 210 miles north to south.