1. On September 23, 1804, members of the Lewis and Clark Expedition arrived at present-day Pierre, South Dakota. This was the site of a major Native American trading center and a significant milestone in the explorers' journey across the western United States.

2. In 1973, on September 23, a group of Native American activists occupied the town of Wounded Knee on the Pine Ridge Indian Reservation. The occupation lasted 71 days and was a pivotal moment in the American Indian Movement's struggle for greater sovereignty and recognition.

3. September 23, 1889, is the date of South Dakota's admission as the 40th state in the Union. The state was formed from the Dakota Territory and has a rich history of Native American cultures, gold mining, and agricultural development.

4. On September 23, 1939, Governor Harlan Bushfield signed a proclamation declaring the first statewide Day of Prayer in South Dakota history. The event was held in response to the outbreak of World War II and drew thousands of people across the state to observe a day of reflection and contemplation.

5. In 1953, on September 23, South Dakota native Tom Brokaw began his career in television journalism. He later became the anchor of NBC Nightly News and a respected commentator on American politics and culture. Brokaw has remained an influential figure in South Dakota and beyond, serving as a role model for many aspiring journalists in the state.