The Castillo de San Marcos is unique in North American architecture. It is the only existing 17th century military construction in the country and the oldest masonry fortress in the United States. Located in St. Augustine, Florida, it was constructed to defend the settlement and the Atlantic Trade Route. Its early use was to protect against pirates, Native American attacks, and European invasions. Later, it served as a military prison during the American Revolution and for Native Americans under U.S. rule.
Who and Why
As Spaniards conquered and colonized the Americas, they were charged with a dual purpose: to bring wealth to the Spanish Crown, and to bring souls to the Catholic Church. They established mission systems across all the lands they claimed, Christianizing the Native Americans and creating an extensive network of farms and information-gathering sources in the process. Africans both free and enslaved were part of Spanish armed forces in Europe and in their first expeditions across the Atlantic.
St. Augustine’s first 100 years were plagued by poverty and pirate attacks. Beginning in its founding year of 1565, nine wooden forts were previously built because rot, termites, storms, tides, and fires destroyed the fragile structures. In 1668, English pirates under the command of Robert Searle attacked the town, killed 60 people, looted every building, and ransomed 70 more people for food, water, and firewood. The pirates also measured the inlet’s depth and took careful notes of its latitude and landmarks, intending to come back and seize St. Augustine and make it their base of operations. After years of petitions, this devastating raid convinced the Spanish crown that La Florida truly needed strong defenses.
How
Queen Regent Mariana of Spain ordered the funding of a more permanent fortification. Constructed over a period of 23 years, from 1672 to 1695 using coquina (a porous limestone formed from the shells of tiny coquina clams). The coquina was cut into smaller, more manageable blocks and used to build the fort's walls. Mortar for the construction was made from lime, produced by burning oyster shells. Cannon balls fired at the walls of the Castillo burrowed their way into the rock and stuck there. The fort's design included various features to make it difficult for attackers to breach, including thick walls, small windows, and an effective internal defense layout.
The 15th century Italian, star shaped design of the Castillo is a result of adapting technological architecture. Black powder weapons propelled the design of new types of defensive structures that could withstand or avoid the cannon projectiles and effectively mount cannons. The most effective structures used the "bastion system” which created projecting diamonds or angle shaped formations.
Bronze and cast-iron cannons and muskets were the primary weapons used at Castillo de San Marcos. Cannons varied in size and caliber, including mortar. They were used for defensive purposes, firing up to 3 miles to attack forces on land and sea.
Both metals were used throughout the 18th and 19th centuries. Cast iron was more commonly used because it was lighter and less expensive, however; it was more vulnerable to the elements and easily rusted. Iron guns would become brittle and dangerous over a short period of time and were subject to exploding. A 24lb. iron cannon cost $21,614, and a bronze cannon $46,374. Less metal was needed to construct bronze weapons, but because of its weight it withstood the stress of firing much better. During colonial times, bronze was preferred for the damp environments of ships and seacoast forts.
The moat was originally designed to serve as a deep, wide ditch in which two drawbridges were needed to cross. Designers chose to keep it dry because during attacks the townspeople and their animals fled to the fortress for protection. Townspeople sheltered inside while their livestock grazed in the dry moat. The tall fortress walls and down sloping hillside protected the food supply for Saint Augustine residents.
The British
British control primarily involved Florida and Gibraltar (a heavily fortified British air and naval base that guards the Strait of Gibraltar, which is the only entrance to the Mediterranean Sea from the Atlantic Ocean). Florida surrendered to British control in 1763 during the French and Indian War, but was returned to Spain in 1783 in the Treaty of Paris, which ended the American Revolution. Gibraltar, on the other hand, surrendered to the British in 1713 under the Treaty of Utrect, and remains a British Overseas Territory today. Spain continues to seek the return of Gibraltar, viewing the British control as a violation of international law. The Gibraltarians, however, have rejected any union with Spain in favor of remaining a British territory.
Native Americans
The Seminole Wars were a series of conflicts between the United States and the Seminole Nation in Florida, lasting from 1817 to 1858. These wars stemmed from disputes over land, trade, and slavery. In 1837, Osceola and roughly 200 other Seminole were held at the fort by the U.S. Army as prisoners of war. Ultimately approximately 4,400 Seminoles were forced to Indian Territory (present-day Oklahoma).
The American Civil War, fought from 1861 to 1865, was a major conflict between the United States and the Confederate States that stemmed from deep-seated disagreements over slavery. Throughout the war, nearly 6,000 Federal troops came through St. Augustine. Most were housed at the St. Francis Barracks while small detachments were also housed on the gun deck of Fort Marion (as Castillo de San Marcos was renamed by the U.S. Army, after Revolutionary War hero Francis Marion) in temporary hutments and tents. A typical day for a soldier would have consisted of guard duty at various locations throughout town, military drills on the fields south of the Barracks, working parties, and foraging the local area for food and supplies to add to their issued rations.
St. Augustine, with its protected harbor, soon became an essential base of operations during the war for blockade runners bringing in vital materials and equipment for the South. Fort Marion served as a transit point for supplies being shipped to the fighting in Virginia and Tennessee, and all but 5 of its 63 cannons were transferred north. With Florida’s fathers and sons leaving to fight far from their home state, General Robert E. Lee, serving at that time as coordinator for Southern coastal defense, decided that the coastline of Florida had to be sacrificed to protect the cattle grazing areas and vital railways of the interior. Small detachments of men were placed at strategic positions along the coastline. Only two companies (totaling roughly 70 men) detached from the 3rd Florida Infantry Regiment made up the garrison stationed in St. Augustine. The war resulted in immense casualties and a significant shift in the United States' political and social landscape, ultimately abolishing slavery and strengthening the federal government.
Now
Three days before Florida officially seceded from the Union, militia arrived in St. Augustine with the intention of taking over the fort and securing the cannons and munitions. Instead, Fort Marion ended up being used to warehouse outdated cannons and arms.
Although the Southern state’s economy was in ruins, the agricultural areas of Florida were largely spared by the war. Florida was able to assist other states in rebuilding by providing lumber and other vital resources. Increased rail lines supported out of state supply transit, thus opening the door for tourism. It took only ten years for Florida’s economy to surpass its pre-war figures.
The National Monument is open for self-guided tours. Immerse yourself in the fort’s history by walking through the fort's casements and viewing the exhibits, watching a musket or cannon demonstration, and listening to formal and non-formal presentations.
For more information on Castillo De San Marcos please visit their website
https://www.nps.gov/casa/index.htm
Or plan a visit to see the Fort in person.
Things To Do - Castillo de San Marcos National Monument (U.S. National Park Service)