1. On September 12, 1890, the town of Mitchell was officially incorporated. Today, Mitchell is most well-known for being home to the world-famous Corn Palace, which attracts thousands of visitors each year.

2. In 1918, an influenza epidemic swept through South Dakota and the country as a whole. On September 12 of that year, the Rapid City Journal reported that the illness had claimed the lives of five people in the western part of the state.

3. Native American leader and civil rights activist Russell Means was born on September 12, 1939 in Pine Ridge, South Dakota. Means played a prominent role in the American Indian Movement during the 1960s and 1970s.

4. The Black Hills National Forest was officially established on September 12, 1897. Today, the forest covers over 1.2 million acres and is home to a diverse range of wildlife, including elk, deer, coyotes, and mountain lions.

5. On September 12, 1917, Camp Lewis was established in Pierce County, Washington. The camp served as a major training facility during World War I, and many soldiers from South Dakota and other states were trained there before being sent to fight overseas.