1. On September 17, 1896, the Iowa State Agricultural Society held its first annual Iowa State Fair in Des Moines. The fair has since become one of the largest and most popular events in the state, featuring agricultural displays, competitions, and entertainment.

2. In 1862, the Battle of Antietam took place in Maryland during the Civil War. Many soldiers from Iowa fought in the battle, including the 9th Iowa Infantry Regiment. September 17 is considered the bloodiest day in American history, with over 22,000 casualties.

3. On September 17, 1958, the Iowa State Board of Regents approved the creation of the University of Northern Iowa in Cedar Falls. The university has since become a leading institution in the state, offering a wide range of undergraduate and graduate programs.

4. In 1880, the first iron bridge in Iowa was built in Johnson County on September 17th. The bridge, which spans the Iowa River, is still in use today and is considered a historic landmark in the state.

5. On September 17, 1998, NASA astronaut Peggy Whitson became the first woman to walk in space. Whitson, who is from Beaconsfield, Iowa, embarked on her historic spacewalk while serving aboard the Space Shuttle Endeavour.