1. On December 21, 1821, Florida was officially ceded from Spain to the United States following the Adams-Onís Treaty. This marked the end of over 300 years of Spanish rule in Florida.

2. In 1939, on December 21, the Edison and Ford Winter Estates were first opened to the public. These estates in Fort Myers were once the winter homes of inventors Thomas Edison and Henry Ford, and today they serve as museums dedicated to their legacies.

3. On December 21, 1974, the iconic Fountain of Youth attraction in St. Augustine was severely damaged by a fire. The fountain, which had been a popular tourist destination since the early 1900s, was eventually restored and reopened several years later.

4. December 21, 2004, marked the deadliest day in Florida's history when an EF3 tornado struck the town of Lake Wales, killing two people and causing extensive damage to homes and businesses.

5. In 2012, the Mayan calendar supposedly predicted the end of the world on December 21. This led to a surge of interest in the ancient Mayan civilization, which was once prominent in the region that is now Florida. Despite widespread media attention, the predicted apocalypse did not occur.