1. Missouri became the 24th state in the United States on December 12, 1821. This day is celebrated every year as Missouri Statehood Day.

2. The Jefferson City Convention, which took place on December 12, 1861, was a pivotal moment in Missouri's history during the Civil War. The convention voted to remain loyal to the Union despite being a slaveholding state.

3. On December 12, 1930, Saint Louis University's head basketball coach, Eddie Hickey, debuted the concept of a six-player team in a match against West Texas State. The new format was successful, and it was adopted by the National Association of Basketball Coaches in 1938.

4. The Missouri Pacific Railroad's Kansas City-Zwolle, Louisiana, line was completed on December 12, 1883. This rail line allowed for easier transportation of goods and people between Missouri and Louisiana, leading to increased economic development in both states.

5. On December 12, 1989, the Missouri Supreme Court ruled in the case of Missouri v. Johnson that the use of roadblocks to combat drunk driving was unconstitutional. This ruling had significant implications for law enforcement practices and civil liberties in the state.