1. On May 11, 1820, the Missouri Compromise was passed by Congress, which admitted Maine as a free state and Missouri as a slave state, thereby preserving the balance of power between free and slave states in the Union.

2. On May 11, 1904, the World's Fair opened in St. Louis, Missouri, providing a platform for showcasing new technology, scientific innovations, and cultural achievements from around the world.

3. On May 11, 1963, civil rights leader Dr. Martin Luther King Jr. was arrested in Birmingham, Alabama, and wrote his famous "Letter from Birmingham Jail" which argued for the moral obligation to resist unjust laws through civil disobedience.

4. On May 11, 1988, Missouri Governor John Ashcroft signed a bill banning smoking in most public places, making Missouri the first state in the Midwest to implement such a law.

5. On May 11, 2013, the six-year-old son of a Missouri pastor, Isaiah Edwards, was kidnapped from his home in Warsaw, Missouri, and later found dead. This tragic incident sparked a nationwide search for the suspect and brought attention to the issue of child abduction and safety.