1. On October 23, 1915, The Missouri State Highway Commission was officially created. The commission was responsible for designing, constructing, and maintaining the state's highways.

2. In 1954, The University of Missouri began its first program in Nuclear Science and Engineering. The program focused on atomic and nuclear physics and was one of the first of its kind in the country.

3. October 23, 1864, marked the beginning of the Second Battle of Westport, also known as the Battle of Kansas City. The battle was fought during the American Civil War and was the largest Civil War battle fought west of the Mississippi River.

4. In 2015, Saint Louis was announced as the host city for the 2020 United States Olympic Trials for the marathon. The trials took place on February 29, 2020, and selected the runners who would represent the United States in the 2020 Summer Olympics in Tokyo.

5. On October 23, 1945, the Truman Library was officially established in Independence, Missouri. The library contains the papers, books, and other materials that belonged to former U.S. President Harry S. Truman. It is one of the thirteen Presidential Libraries in the United States.