1. On September 19, 1857, the United States Army established Fort Randall in what is now South Dakota. The fort served as an important outpost in the western territories and played a key role in conflicts with Native American tribes.

2. The South Dakota State Fair opened on September 19, 1889, marking the first time the state held its own agricultural exposition. Today, the fair is one of the largest events in the state, attracting visitors from across the region.

3. The first airplane to land in South Dakota touched down in Pierre on September 19, 1911. The plane was a Curtiss biplane piloted by Harold Kantner, and his flight helped spark interest in aviation across the state.

4. On September 19, 1961, the Oahe Dam on the Missouri River was completed after several years of construction. The dam is one of the largest in the United States and provides hydroelectric power to millions of people in the region.

5. In 2002, the Crazy Horse Memorial in the Black Hills of South Dakota was expanded with the installation of a massive sculpture of Chief Crazy Horse riding his horse. The sculpture is still under construction and will eventually stand more than 500 feet tall.