1. On September 10, 1821, Missouri was admitted as the 24th state of the United States. Prior to its admission, Missouri had been a part of the Louisiana Territory and was a center of conflict during the debate over the expansion of slavery.

2. In 1897, the City of St. Louis opened its first public library on September 10. The library was housed in the Bent-Bonne-Apartment Hotel and had a collection of 10,000 books.

3. On September 10, 1917, future President Harry S. Truman enlisted in the Missouri National Guard. Truman would go on to serve in World War I and eventually become the 33rd President of the United States.

4. The first professional football game in Kansas City was played on September 10, 1960. The Dallas Texans (now the Kansas City Chiefs) defeated the Los Angeles Chargers 21-20 in the American Football League's inaugural season.

5. On September 10, 1977, the Missouri State Penitentiary in Jefferson City was the site of a major prisoner uprising. Approximately 1,000 prisoners took control of the prison, holding several guards hostage. The situation was eventually resolved through negotiations, but not before four inmates were killed and several others were injured. The incident prompted reform efforts within the state's prison system.