On November 2, 1889, North Dakota and South Dakota were admitted to the Union as the 39th and 40th states. The first European explorers, Louis Joseph and François de La Vérendrye, entered the region in 1742 and 1743. At that time, at least eight Native American tribes populated the vicinity including the Mandan, Arikara, Kidatsa, Assiniboin, Crow, Cheyenne, Cree, and the Dakota (Santee Sioux).
Other than through fur trapping, exploration of the Dakotas by European-Americans was practically nonexistent prior to the 1803 Louisiana Purchase. In 1804, the Lewis and Clark Expedition wintered in present day North Dakota.