1. The Dakota Territory was established on February 23, 1861. This marked the creation of the Dakota Territory, which included the area that is now North Dakota and South Dakota, as well as parts of Montana and Wyoming. The territory existed until November 2, 1889, when the two states were admitted to the Union.

2. South Dakota enacted the first state income tax on February 23, 1935. In an effort to provide funding for the state during the Great Depression, South Dakota became the first state to implement a state income tax, with rates ranging from 1.5% to 4%. The income tax remains a significant source of revenue for the state.

3. On February 23, 1899, the first auto dealer in South Dakota, the Marble Motor Company, opened in Sioux Falls. The company sold single-cylinder Oldsmobiles for $650 each. The auto industry would go on to have a significant impact on the state, with major manufacturing plants like the Ford Motor Company's assembly plant in St. Paul and the General Motors manufacturing plant in Sioux Falls.

4. February 23, 1929, marked the opening of the Black Hills Passion Play in Spearfish. The play, which tells the story of Jesus Christ, is performed annually in an outdoor amphitheater in the Black Hills. It has become a popular attraction for tourists and residents alike, with performances taking place from May through September.

5. On February 23, 1972, the Sturgis Motorcycle Museum and Hall of Fame was founded. The museum, which is located in Sturgis, is dedicated to preserving and promoting the history of motorcycles and their cultural impact. It features a collection of vintage motorcycles, as well as exhibits on motorcycle racing, customization, and culture. The museum has become a popular destination for motorcyclists visiting the area for the annual Sturgis Motorcycle Rally.