1. On August 13, 1861, the Battle of Wilson's Creek, which was fought in Greene County, Missouri, occurred. It was the first major battle in the Western Theater of the American Civil War, and it resulted in a Confederate victory.

2. The first flight in Missouri took place on August 13, 1908, when Professor A.C. Houck made a successful flight in his homemade airplane in Cape Girardeau.

3. The Missouri State Fair is traditionally held in August, and on August 13, 1921, it officially opened its gates for the first time in Sedalia. Today, the fair is one of the largest in the United States and attracts more than 300,000 visitors each year.

4. On August 13, 1948, Senator Harry S. Truman, who was born in Lamar, Missouri, accepted the Democratic Party's nomination for President of the United States. Truman went on to defeat Republican candidate Thomas E. Dewey in the general election.

5. On August 13, 1961, construction of the Union Electric Building (now called the AmerenUE Building) was completed in St. Louis. At the time, it was the tallest building in the city and the second-tallest in the state. Today, it is still one of the most recognizable landmarks in downtown St. Louis.