1. Missouri became a state: On April 9, 1820, President James Monroe signed the Missouri Compromise, which allowed Missouri to join the United States as a slave state, and Maine to join as a free state. This compromise helped to ease tensions between the North and South over slavery in the United States.

2. A famous battle occurred: On April 9, 1864, the Battle of Pleasant Hill took place in Louisiana during the Civil War. Missouri soldiers fought on both sides, with over 300 Missourians losing their lives in the bloody confrontation.

3. A famous Missourian was born: On April 9, 1898, Paul H. Douglas was born in Massachusetts. He later moved to Missouri and served as the state representative for Missouri's 5th congressional district from 1943 to 1949. Douglas went on to become a United States Senator representing Illinois from 1949 to 1967.

4. A tornado devastated a town: On April 9, 1947, the town of Woodward, Missouri was struck by an F5 tornado, one of the most powerful tornadoes ever recorded. The tornado left 185 people dead and caused over $13 million in damages.

5. The St. Louis Cardinals played their first game: On April 9, 1892, the St. Louis Cardinals played their first game as a Major League Baseball team. They defeated the Chicago Colts (now the Chicago Cubs) by a score of 10-9. The Cardinals have since become one of the most successful and storied franchises in baseball history.