1. In 1887, the first railroad to lead into the Black Hills was completed, marking a significant milestone in South Dakota's transportation history. The Chicago & North Western Railway made its way into Deadwood, South Dakota, after a decade of planning and construction.

2. On September 4, 1918, Public Law 303 authorizing the construction of a national cemeteries system was established by Congress. This important legislation led to the development of the Black Hills National Cemetery, one of the most well-known cemeteries in the United States.

3. In 1962, the first full-scale underground gold mine in South Dakota was opened, the Homestake Mine in Lead, which would eventually become the largest and deepest gold mine in North America. It quickly became a significant economic driver for the state, providing jobs and a boost to the local economy.

4. On September 4, 1986, the John Donne Hubbard Museum of South Dakota was established in Kimball, South Dakota. The museum features a wide range of exhibits and collections focused on the natural history of the state, including paleontology, mineralogy, and botany.

5. In 2008, a significant wildfire swept through the Black Hills of South Dakota, destroying hundreds of homes and businesses and forcing the evacuation of thousands of people. The blaze, which started on September 4, ultimately burned more than 87,000 acres of land, making it one of the most destructive fires in the state's history.