South Dakota was the 40th state in the USA; it became a state on November 2, 1889. - State Capital is Pierre. - Nickname is Mount Rushmore State. - South Dakota's official flag was adopted in 1963. The flag is sky blue with state seal in the center (surrounded by yellow rays are the words, "South Dakota" and "The Mount Rushmore State"). South Dakota's state seal pictures a farmer plowing a field, a river, forests, mountains, a steamboat, and the motto, "Under God the People Rule." South Dakota's original flag (adopted in 1909) had an image of the sun on the front and the state's seal on the back. In 1963, the state's seal and the sun's rays were both placed on the front of the flag (with nothing on the back of the flag). In 1992 the old motto, "The Sunshine State," was changed to "The Mount Rushmore State" (this is because Florida is commonly known as the Sunshine State). The original flag's design was by Senator Ernest May and Doane Robinson, secretary of the State Historical Society. Will Robinson, Doane Robinson's son, redesigned the flag in 1963.