1. On September 17, 1861, the Battle of Lexington began when Confederate General Sterling Price led an attack on Union troops in Missouri. The battle lasted for three days and resulted in a Confederate victory.

2. On September 17, 1950, St. Louis Browns player Jim Dyck hit three home runs in one game against the Boston Red Sox. This feat made Dyck the first player in baseball history to hit three homers in his first three plate appearances of a game.

3. On September 17, 1976, the St. Louis Cardinals defeated the New York Mets 4-3 in the longest game in National League history. The game lasted 25 innings and took 7 hours and 4 minutes to complete.

4. On September 17, 1988, the Missouri Ozark Music Festival was held in Steelville, Missouri. The festival featured performances by over 30 bands and drew an estimated 25,000 attendees.

5. On September 17, 2006, the Gateway Arch in St. Louis was closed for several weeks due to a mechanical failure. The malfunction occurred in the tram system that takes visitors to the top of the arch, and repairs took longer than expected.