1) The state of Missouri was admitted to the United States as the 24th state on September 18, 1820. This followed the Missouri Compromise, which allowed Missouri to enter the Union as a slave state while Maine was admitted as a free state, maintaining the balance of free and slave states in the country.

2) On September 18, 1906, James “Lucky” Baldwin, one of the wealthiest men in America and a prominent racehorse owner, died at his estate in Arcadia, California. Baldwin was born in Indiana but spent much of his life in Missouri, where he owned extensive mining interests and was a key figure in the development of Leadville, Colorado.

3) September 18, 1956 saw the death of Robert A. Taft Jr., the son of former U.S. Senator Robert Taft and himself a prominent Republican politician. Taft Jr. served in the U.S. House of Representatives and the U.S. Senate before becoming Governor of Ohio in 1963. He was a leading conservative voice during the 1960s and 1970s, and was considered a potential candidate for the Republican presidential nomination in 1976 before losing a close primary race.

4) The St. Louis Cardinals clinched their third National League Central division title in a row on September 18, 2015, defeating the Chicago Cubs 4-3. The Cardinals went on to win their first playoff series that year before falling in the NL Championship Series.

5) September 18, 2019 marked the opening of the Gateway Arch National Park Museum in St. Louis, Missouri. The museum, which cost $176 million to build, tells the story of the Westward Expansion of the United States and the important role that St. Louis played in that history. It features interactive exhibits and 4D presentations, as well as artifacts and historical documents.