St. Augustine Forts: Defending America’s First City

Founded in 1565, Spain established the city of St. Augustine to protect its shipping route and claim to “La Florida.” Castillo de San Marcos was tasked with defending the town from encroaching British colonies in the north. Over a span of 80 years, the Spanish built nine wooden forts before constructing the Castillo de San Marcos between 1672 and 1695.

CASTILLO DE SAN MARCOS

The Castillo was constructed in a star-shaped pattern in order to use the cannon fully. The shape of the Castillo allowed a battery of cannons to create interlocking fields of fire. 

The star-shaped design, combined with the diamond-shaped corner bastions and curtain wall, created a deadly crossfire able to repel any enemy. The vast open space at the base provided zero cover for enemy infantry, and thick walls deflected the incoming cannonballs with their rising slopes. Combined with the Ravelin, a triangular fortification that shields the sally port entranceway from attack, the Castillo was impenetrable.

The Castillo is constructed from native Florida Coquina “stone.” Over time, the tiny coquina clam donax variabilis accumulated in layers several feet thick. The coquina stone was quarried from the Kings Quarry in nearby Anastasia Island. Masons and engineers were brought in from Spain, with prisoners and soldiers from Cuba. Oyster shells were burned into lime, mixed with sand and water to create mortar, and construction began.

The walls were, on average, 12 feet thick, with walls facing the ocean as thick as 19 feet. The extreme thickness was because no one knew how strong coquina was or how much punishment it could take.

The answer was discovered in 1702 when the Governor of Charleston, James Moore, led his forces to St. Augustine and laid siege to the city. He quickly captured the town and set up his cannons. The attack on the Castillo began. Townsfolk and soldiers were braced for the impact of cannon fire. But the attack did not destroy the Castillo. The coquina held and absorbed the shock of impact. The cannonballs either bounced off or sunk into the wall a few inches. The Castillo was tested again in 1740 when Georgia Governor James Oglethorpe blockaded St. Augustine harbor and Matanzas inlet. The Castillo withstood a 37-day siege.

In 1763, politics accomplished what war couldn’t. As part of the Treaty of Paris that ended the French and Indian War, Florida was transferred to Britain in 1763. The remaining Spanish and Timucua returned to Cuba, and the Castillo, now renamed Fort St. Mark, is in British hands. 

Twenty years later, in 1783, a treaty resulting from the American Revolution returned Florida to Spain.

In 1821, the U.S. ratified Florida’s cession from Spain, and, in 1825, the Castillo was renamed Fort Marion in honor of Revolutionary War hero General Francis Marion, aka the “Swamp Fox.”

From 1861 to 1862, Confederate forces occupied Fort Marion. Florida seceded from the Union, and Union troops left the fort, leaving only one man behind as a caretaker. When militiamen came to take over the fort, the caretaker wouldn’t leave unless he was given a receipt for it from the Confederacy. He got his receipt and left. 

Fort Marion was taken without firing a shot.

In March 1862, Union naval forces arrived, and once again, Fort Marion was taken without a shot, as the Confederate troops left the night before in anticipation of Union forces coming.

In 1924, Fort Matanzas and Fort Marion (the Castillo) were transferred to the National Park Service, but from 1942 to 1945 the grounds were used as a Coast Guard Training Base.

THE DRY MOAT

During the British Siege in 1702, staying in the city proved very dangerous, so about 1,500 townspeople moved into the Castillo, with livestock in tow, and the moat became a corral, allowing animals to graze and help feed the people. The moat served a tactical purpose as well. It protected the walls of the Castillo from cannon fire, and the vast open space exposed attackers to fire from soldiers stationed above on the gundecks.

The siege lasted 51 days, but the townsfolk were protected within the fort’s walls. As reinforcements from Cuba arrived, the British forces retreated, burning the city to the ground as they fled.

The moat was filled with water in 1938, but, in 1996, returned to its original state by the park service due to damage to the Castillo’s foundation.

ARMAMENT

The gundeck of Castillo de San Marcos currently houses various caliber cannons and mortars constructed of cast iron and bronze, which represent the different types of armaments used by assorted nations during various battles throughout the Castillo’s history.

The cannons produced in Spain are true works of art. Made of bronze, they’re easily identified by their green patina, and the Spanish also equipped them with banners and gave them such titles as La Sibila (The Fortune Teller), Abajado (Crouching One), and Facheno (Braggart). Four of the Castillo’s cannons have a second banner that reads “Violati Fulmina Regis” (thunderbolts of an offended/angry king).

On the eastern side of the gundeck, facing the water, three replica 6-pound cast-iron cannons are set up for reenactments.

HOT SHOT FURNACE

The goal of the Hot Shot was to set enemy ships on fire. Cannonballs were put into the furnace and heated to 1,500 degrees, then two soldiers carried the shot with tongs to a nearby cannon on the Water Battery.

FORT MATANZAS

Overlooked by many, Fort Matanzas sits south of the city on the Matanzas River. After arriving at the ranger station, guests are transported to the fort by pontoon boat and begin the tour given by National Park Service Rangers.

After Castillo de San Marcos was finished in 1695, St. Augustine still had one weakness: Matanzas inlet. Located 14 miles south of the city, the inlet allowed access to St. Augustine via the Matanzas River, and enemy ships would be able to mount an attack on the town from the rear, out of the reach of the Castillo’s cannon battery.

The Fort could handle a maximum of 50 men during a crisis, but standard manning was one officer, four infantrymen, and two gunners. The crews were rotated from St. Augustine to serve one month of duty. The soldiers lived in the room off the gun deck, while the officer lived in the room above them. Soldiers pulled duty on the gun deck while the officer was stationed on the observation deck looking for enemy sails.

The armament consisted of five guns: four 6-pounders and one 18-pound gun. 

The Matanzas inlet got its name from Spanish Admiral Pedro Menéndez de Aviles. Menéndez was sent to Florida by Philip II of Spain to establish a settlement and remove the French Protestants (Huguenots), who had established a beachhead at Fort Caroline near Jacksonville.

In May 1565, Jean Ribault set sail from France to resupply Fort Caroline. When Menéndez arrived at the mouth of the St. Johns River to oust him, there was a brief sea chase but no battle, after which Menéndez made port in the newly established outpost of St. Augustine.

In September 1565, Ribault made way for St. Augustine to attack the city. Unfortunately, his luck ran out, and a hurricane pushed his ships further to the south and wrecked them past what is today known as Daytona Beach. 

In the meantime, Menéndez marched on Fort Caroline and was given an easy victory as the French soldiers had already left. As he returned to St. Augustine, the native Timucuan tribe told him of a group of men on the beach a few miles south of the city.

Menéndez took 50 soldiers and headed for the inlet, where he found almost 130 shipwrecked Frenchmen. Menéndez told the men that Fort Caroline had been captured and advised them to surrender, but he could not guarantee clemency. 

As the men were hungry, tired, and lost most of their weapons in the shipwreck, they surrendered. Menéndez marched them across the inlet and executed all but 16 men — four artisans needed to help construct the Castillo and 12 Catholics.

Several weeks later, more survivors, including Ribault himself, wound up on the beach. Menéndez offered them the same deal, and again the men were executed. Almost 250 men were executed, and the legend is that the Matanzas River flowed red with blood. From then on, the inlet was known as “Matanzas,” the Spanish word for slaughters.

In 1740, Governor James Oglethorpe blockaded St. Augustine harbor and Matanzas inlet with ships from the British colony of Georgia. The blockade began a 37-day siege of the town, but a few Spanish ships managed to break through and provide resupply. With the hurricane season beginning, Oglethorpe retreated to Georgia.

To prevent a future attack, the construction of Fort Matanzas began in 1740 and was completed in 1742. While the fort was much smaller, it was built in the same manner as the Castillo and constructed of coquina, using convicts from Cuba and Spanish soldiers for labor.

In 1742, as the Fort was nearing completion, Oglethorpe returned with 12 ships. As the scouting ships approached, they were surprised by cannon fire from the newly constructed fort and left. By the mid 1800s, Fort Matanzas fell into disrepair, with its foundation failing and cracks appearing throughout. Restoration began in 1916 to preserve the fort’s historic value.

ST. AUGUSTINE

A trip to Florida isn’t complete without visiting America’s oldest city, St. Augustine, and a trip to St. Augustine isn’t complete without a visit to Castillo de San Marcos and Fort Matanzas. The city and the Castillo give you a glimpse into the beginnings of European ventures into the new world and the early days of America. 

Castillo De San Marcos

Address: 11 South Castillo Dr., St. Augustine, FL 32084

Hours: Castillo de San Marcos is open to the public seven days a week, except Thanksgiving and Christmas. The first admission is at 9 a.m., and the last is at 5 p.m. The Castillo closes and visitors must exit at 5:15 p.m. The park grounds are closed from midnight until 5:30 a.m.

Admission: Adults (ages 16 and above): $15, valid for 7 consecutive days. Children (ages 15 and under) are admitted free of charge but must be accompanied by an adult.

URL: nps.gov/casa

Fort Matanzas National Monument

Address: 8635 A1A South, Saint Augustine, FL 32080, (904) 471-0116