1. South Dakota became a state on November 2, 1889. However, on September 26 of that year, President Benjamin Harrison signed the proclamation admitting both North Dakota and South Dakota into the Union. This event marked the end of a long and bitter rivalry between the two territories that disputed which would become a state first.

2. In 1913, the town of Belle Fourche, South Dakota, became the recognized "Geographic Center of the Nation" due to its position at the exact center of the United States when Alaska and Hawaii are included. Each year on September 26, Belle Fourche hosts the "Center of the Nation Day" celebration, drawing visitors from across the country.

3. On September 26, 1959, the first "Corn Palace Festival" was held in Mitchell, South Dakota. The festival celebrates the city's iconic "Corn Palace," a building decorated entirely with corn and other grains each year. The festival features live music, carnival rides, and other events, culminating in the crowning of the Corn Palace Queen.

4. In 1982, the state of South Dakota sued the federal government over the ownership of the Minuteman Missile silos located throughout the state. The lawsuit alleged that the federal government had not compensated the state for the use of its land, and sought $45 million in damages. On September 26, 1985, a federal court ruled in favor of the state, requiring the government to pay South Dakota $28.1 million.

5. September 26, 2019 marked the 80th anniversary of the dedication of the Mount Rushmore National Memorial, located in the Black Hills of South Dakota. The monument features the 60-foot heads of former U.S. presidents George Washington, Thomas Jefferson, Abraham Lincoln, and Theodore Roosevelt, and draws millions of visitors each year.