South Dakota became the 40th state of the Union on November 2, 1889! It’s named after the Dakota Sioux people, but you can also call it The Mount Rushmore State! Its capital is Pierre, and its largest city is Sioux Falls! South Dakota’s state motto is “Under God the People Rule!” This state is famous for its massive stone monuments—Mount Rushmore and Crazy Horse—as well as the battles of Wounded Knee and Little Bighorn, the Wild West town of Deadwood, Black Hills gold, and the annual Sturgis Motorcycle Rally!