History of St. Augustine and Castillo de San Marcos
St. Augustine (estab. 1565) is the oldest Eurocentric city in the United States (55 years older than Plymouth, MA.) The site was discovered by Ponce de Leon (discoverer of the Gulf Stream) on Easter, 1513. Over the next century, British pirates and corsairs pillaged and burned the town on several occasions and this led to building the fort of Castillo de San Marcos starting in 1672 and finished in time to withstand a two month British siege in 1702. The fort was originally designed for storing food in case of a siege. British attacks continued after 1702, however, as Plantation and slave owners in the English colonies resented the slave sanctuary that Spanish Florida afforded (the first Underground Railroad.) This quickly led to the first free Black settlement in the future United States (Fort Mose, formed just north of St Augustine). Another stronger attack in 1740 by the Georgia governor (James Oglethorpe) also failed.
The fort never fell but a 1763 treaty gave Florida to the British. Then in 1783, as the second Treaty of Paris gave the southern U. S. colonies their freedom, Florida was again Spanish.
The Adams-Onîs Treaty of 1821, peaceably turned over the Spanish colonies of East and West Florida and, with them, St. Augustine, to the United States. The fort was renamed Fort Marion and Florida became a State in 1845.
The U. S. used the fort as a military prison to hold Seminoles and members of western tribes, including Kiowa, Cheyenne, and Geronimo’s band of Chiricahua Apache. Drawings of Spanish Galleons and a Kiowa Sun Dance still be seen on some of the inside walls.