1. The first official game of basketball was played in Indiana on September 21, 1891. James Naismith, a Canadian physical education instructor, invented the game at the International YMCA Training School in Springfield, Massachusetts, and a student from Indiana named C.H. Page helped popularize it in the Hoosier State.

2. On September 21, 1903, the Indiana State Fair opened in Indianapolis for the first time at its current location on 38th Street and Fall Creek Parkway. The fair, which has been held annually since 1852, is known for its midway rides, agricultural exhibits, and famous "state fair foods" like deep-fried butter and pork tenderloin sandwiches.

3. One of Indiana's most famous authors, Kurt Vonnegut Jr., was born in Indianapolis on September 21, 1922. Vonnegut wrote acclaimed novels like Slaughterhouse-Five and Cat's Cradle that explored themes of war, technology, and human nature. He died in 2007 at the age of 84.

4. The first day of fall, also known as the autumnal equinox, usually occurs on September 22 or 23, but it can occasionally fall on September 21. The equinox marks the moment when the sun is directly above the equator and the length of daylight and darkness is roughly equal all over the world.

5. September 21, 1985 was a historic day for Indiana sports fans, as the Indianapolis Colts won their first game in over a year by defeating the Buffalo Bills 14-6. The Colts, who had gone 0-13 in the previous season, were led by rookie quarterback Jack Trudeau and running back Randy McMillan. The team celebrated its victory by dumping a cooler of Gatorade over head coach Rod Dowhower.