1. On July 20, 1861, the Battle of Boonville took place in central Missouri during the Civil War. Union forces, led by Nathaniel Lyon, defeated a small Confederate force, marking the first significant victory for the Union in the war.

2. In 1923, the Mark Twain Memorial Bridge opened to traffic on July 20. The bridge spans the Mississippi River between Hannibal, Missouri and Illinois, and is named in honor of the famous Missouri author.

3. On July 20, 1950, the Kansas City Monarchs played their first game in Municipal Stadium, which would become their home field for the next several years. The Monarchs were a storied baseball team in the Negro Leagues, and their players included legends such as Satchel Paige and Jackie Robinson.

4. In 1969, Apollo 11 astronaut Neil Armstrong became the first person to walk on the moon on July 20. Although he was from Ohio, Armstrong had ties to Missouri through his work at the McDonnell Douglas Corporation in St. Louis, which helped design and build spacecraft.

5. On July 20, 1976, Missouri Governor Christopher "Kit" Bond signed the Missouri Human Rights Act into law. The act prohibited discrimination in housing, employment, and public accommodations based on characteristics such as race, religion, and gender. It was seen as a landmark civil rights achievement in the state.