associated with Hurricane Dennis severely flooded the town, causing major damage to local businesses and homes. History Originally known as San Marcos de Apalache and centered on a Spanish fort, this town was founded by the Spanish in the 17th century in what was then Spanish Florida. There was a trading post of Panton, Leslie & Company in the late 18th century. A long time has passed since St. Marks last had appreciable importance, but this place on Apalachee Bay in Florida's Big Bend is a very old and historic Gulf port. Fortifications built here by the Spanish in the 17th century, and rebuilt several times, provided the venue for force of arms repeatedly up through the American Civil War. In the best-known incident, Andrew Jackson, in his incursion into Spanish Florida in 1818, executed British nationals Robert Chrystie Ambrister and Alexander George Arbuthnot at the old fort, as well as the Muscogee ("Creek") religious leader called Francis the Prophet. This nearly embroiled the United States in international strife. San Marcos de Apalache Historic State Park interprets the site of the old fort. Today's St. Marks evidently has its roots in American commercial activity that took hold beneath the walls of the fort upon acquisition of Spanish Florida by the U.S. in 1821—before the settlement moved slightly up the St. Marks River to the present position. Various articles in publications like Florida Historical Quarterly relate how the fort site later held a government "naval" hospital to meet yellow fever emergencies in the merchant marine. And just afterward Confederate batteries were established on the site in the Civil War. Their earthworks remain and are interpreted in the historic state park. But the site also exhibits old Spanish stonework, and not far away (though inaccessible), just down St. Marks River are shallow Spanish quarries where this limestone was evidently obtained in the 1730s. Limestone quarried here by the Spanish helped to make the St. Marks Light lighthouse, constructed about 1830 by the U.S. government. The lighthouse stands, after a couple of reconstructions, at the mouth of the river six miles from town and accessible by road. The lighthouse is, like San Marcos de Apalache, on the National Register of Historic Places. St. Marks was a seaport for all of Middle Florida and lower Georgia during this early period. Ellen Call Long, on her way to Tallahassee, described the port about 1830 as