Not long after Pedro Menendez de Aviles founded St Augustine in 1565, the need for a fortified structure became evident. Over the next 100 years, nine wooden forts were built at various sites throughout the settlement.
After an attack by English pirate Robert Searle in 1668, Governor Francisco de la Guerra petitioned Mariana, Queen Regent of Spain, for a masonry structure to be built to protect the citizens of St. Augustine and Spain’s interest in the region. Construction of the Castillo de San Marcos began in October 1672.
Made from the stone coquina, Spanish for shells, the fort was built by Native American laborers and workers brought in from Havana, Cuba over the next 23 years. It was completed in 1695.
Coquina, which is a similar to limestone, is a composite of small shells that have bonded together. The coquina used to build the Castillo was quarried from nearby Anastasia Island and ferried across the Matanzas Bay to the construction site.
The stone proved very effective in absorbing the impact of shells from English cannons, which made it an invaluable tool in the survival of the fort as well as the city of St. Augustine.
Over the next 120 years, Spain and England fought for control of Florida, and ownership of the fort was traded back and forth between them. Though the fort now bears its original name, during the British occupations it was called both Fort St. Mark and Fort Marion.
Eventually, Britain gained control of the fort through the 1819 Adams-Onis Treaty, which left Texas to the Spanish and ceded Florida to the United States.
During the Civil War, Confederate soldiers took control of the fort without firing a shot in January 1861, but they did not hold it for long. Along with the city of St. Augustine, the fort was re-occupied by Union troops in March 1862 when acting mayor Cristobal Bravo surrendered to Union Navy fleet commander C.R.P. Rodgers.
Post-Civil War, the fort was used to house prisoners from the Indian wars in the West as well as deserters from the Spanish-American War. In 1900, the fort was taken off the active duty rolls after more than 200 years of service.
Castillo de San Marcos is open daily from 8:45 a.m. to 5:15 p.m. Admission is $7 for adults. Children 15 and under are free. For information, call 904-829-6506 or go to nps.gov/casa.