1. First Spanish Settlement Established in Florida: On March 20, 1565, the Spanish established the first permanent settlement in Florida, St. Augustine. The settlement was founded by Spanish explorer Pedro Menéndez de Avilés, who named the settlement after the Patron Saint of Florida, St. Augustine of Hippo.

2. Florida Secedes from the Union: On March 20, 1861, Florida became the third state to secede from the Union and join the Confederacy during the Civil War. The secession was prompted in part by Florida's pro-slavery stance and fears of abolitionist movements in the North.

3. First Commercial Jet Flight in the United States: On March 20, 1958, National Airlines made history by launching the first commercial jet flight in the United States with a Boeing 707. The flight departed from Idlewild Airport in New York City (now JFK International Airport) and landed in Miami, Florida, marking the dawn of the jet age in America.

4. Florida Everglades National Park Established: On March 20, 1947, President Harry Truman signed legislation establishing the Florida Everglades National Park, a unique and fragile ecosystem that spans over 1.5 million acres in southern Florida. The park is home to numerous rare and endangered species, including the Florida panther and American crocodile.

5. Florida State University Founded: On March 20, 1851, the Florida State Legislature authorized the creation of the West Florida Seminary, which would later become Florida State University. The university is now one of the largest and most respected institutions of higher education in the Southeastern United States.