1. On September 15, 1821, Florida became a United States territory. Prior to this, it had been a Spanish colony.

2. In 1963, the first game of the American Football League's Miami Dolphins was played on September 15 at the Orange Bowl. The Dolphins lost to the Oakland Raiders with a score of 23-14.

3. September 15, 2004 marked the opening of the Perry Oldenburg House in Tallahassee. The historic home was built in the late 1800s and is now an important cultural site in the area.

4. On September 15, 2018, Hurricane Florence (later downgraded to a tropical storm) hit Florida, causing flooding and damage in several areas.

5. The annual Miami Broward Carnival takes place on or around September 15, bringing together thousands of people to celebrate Caribbean culture with music, food, and dancing.