Fort+Mifflin


 * Renaissance Influence on Fort Mifflin and American Warfare **

**Introduction**

Fort Mifflin was built on Mud Island in the Delaware River in 1771 with initial guidance from engineering captain John Montresor. It was a key reinforcement for defense in 1777, after the embracing of the Declaration of Independence, as British troops landed in Maryland and pushed towards Philadelphia in attempts to take over the capital. During this time, Fort Mifflin experienced the largest attack ever witnessed in North America as it endured a 5 week battle with the British Navy. Reconstruction of the Fort did not begin until 1795 where, by the design of Pierre L’Enfant, it became part of the First Coastal Defense System. This research and analysis will explain the military and strategic development of one of the most important forts in America. It can be deduced that Fort Mifflin incorporated Renaissance fortification design in its construction which influenced development of colonial American warfare despite the fact that these techniques were hundreds of years old. Fort Mifflin was employed in some way during all major military action that the country was involved in. It was closed in 1954 as the oldest fort in constant use in the country and was signed back to the city of Philadelphia in 1962. **Designs of John Montresor**

 The building and development of the fort came in 3 distinct steps. Governor John Penn recognized the importance of protecting the port of Philadelphia from invasion and hired engineering captain John Montresor to take on the task. Montresor proposed 6 designs to the Board of Commissioners. Totaling over £  40,000, the plan included “32 pieces of cannon, 4 mortars, and 4 royal howitzers” [1]. The cannon is one of the oldest pieces of military artillery, dating back to the 3rd century B.C. Medieval Europe saw the emergence of the metal cannon and by the Renaissance era cannons were made larger, more powerful, and mobile. As a result of using cannons as a means of destruction against the enemy, the infrastructure of forts adapted as necessary. They took on the shape of a star and were built with angles and thick, sloping walls to defend against the cannon [3]. To further strengthen the design, another renaissance application known as a bastion was also incorporated into the structure and will be further discussed later. The mortar is a type of weaponry that was first found in the designs of Leonardo da Vinci as he recognized that renaissance Italy was always unavoidably stuck in war [4]. The advantage of these was its ability to drop shells on short-range targets because the ballistic trajectory was in the path of a high arch. Originally designed as large, heavy pieces of artillery, they evolved over time and eventually became lighter and transportable. The howitzer comes from the German word haufnice, which means crowd. It is a short-barreled artillery piece commonly supported atop 2 wheels for easy transportation designed to combat advancing troops (common tactic of German medieval armies) [5]. Despite the strong design of the fort, which was to be equipped with proper artillery yet able to defend against the same, the design was deemed too expensive by the governor and Board of Commissioners. They did not provide adequate funding so Captain Montresor left to resume his prior duties and left the outlines of the fortification to the head workman [1]. **Philadelphia Committe of Public Safety**

The next step in building the fort was during 1776 when work was resumed by the Philadelphia Committee of Public Safety, led by Benjamin Franklin. He recognized the need for blocking the Delaware River to deny access to Philadelphia, now the largest city in America. Since Britain had the best Navy in the world and a blockade would not be strong enough, French designed marine chevaux de fries were implemented. Meaning underwater fence, they were Renaissance defense mechanisms made of wooden frames fastened with long pieces of sharp iron that would pierce the bottom of any ship that passed over it [6]. There were two tiers of chevaux de fries through the main channel of the Delaware with additional tiers eventually placed all the way to Marcus Hook [2]. These tiers were a tough defense against opposing vessels as they would not know where the gaps were located, which were implemented to allow for the passing of friendly ships. Ships that got caught in the defense system became an easy target for open fire from Fort Mifflin. One of the first tests on Fort Mifflin came in October 23, 1777 when a British Royal Navy fleet attempted to open supply lines along the Delaware River for the British army that had recently taken over Philadelphia. Despite their efforts, they were bombarded by artillery and cannons from Fort Mifflin. The Americans managed to damage six ships, two of which ran aground and were destroyed. This battle was the beginning of what turned into the longest bombardment in the American Revolution till Fort Mifflin was abandoned on November 16, 1977 [7]. After it was burned to ruins and overran by the British, Pierre Charles L’Enfant took over reconstruction in 1795. The fort was officially closed in 1954 as the oldest fort in America in constant use.

**Excavation Analysis of Structural Components**

The renaissance influence is most apparent in the building techniques of the fort which were best analyzed when the Philadelphia Historical Commission funded an archaeological investigation to determine the cause of the sinking of the north-west salient of the fort. The main finding of the excavation was a thick stone wall in the shape of a pentagon. It was concluded that these walls constituted a counterfort which was a structure found in European fort design during the seventeenth century. They particularly relate to French design origins of masonry reinforcing of the ramparts. The shape of the pentagon also refers to the star-shaped fortification suggested by Montresor to defend against enemy cannons and other heavy artillery. More accurately described, and further confirmed upon findings of other structures within the fort design, counterforts are “masonry structures added to the rampart along the side of the terreplein of the same height as the rampart, to aid the support of the earth” [8]. French influence upon colonial America and its military is most evident through American attraction for products of French civilization along with the fact that the French were masters of their trade in military science, most specifically architectural design. In the overall design, Fort Mifflin resembles European fortifications such as those in France and Germany, amongst others, who most commonly used counterforts to reinforce their salient angles [8]. Other building techniques used in fortification structures that can be traced to Renaissance origins include bastions, ramparts, and terrepleins. Bastions are a type of projection that extends from the main fortification. A bastion normally takes on the shape of a point, as seen in both Fort Mifflin and many European fortifications. The design can be dated back to the late fourteen hundreds and the structures developed by the Florentine family of Sangallo. The brothers reconstructed forts for prominent leaders of Italy which took on the shape of a pentagon and included varying amounts of bastions. The pentagon-shape of walls of certain parts of the fortification is a recurring theme throughout European design. Their designs show that the bastions were also supported by a structure similar to that of a counterfort [9]. This was proven during the excavation study at Fort Mifflin that indeed the bastions were supported by the counterfort. The reason this investigation began was due to the visible sinking of the rampart. As seen in the analysis of structural components, ramparts are a large mound of earth elevated to a height that would be able to defend against the enemy. Ramparts are defensive walls and have been found to protect cities and towns since before Christ. Their more strategic and prominent use can be found during the Renaissance when they were built larger and studded with towers for better defense purposes. The terrepleins followed the rampart inside the walls of the fortification and were an area where artillery could be mounted [8].

**Conclusion**

Almost all technical components of the fort have origins tracing back to Renaissance fortification designs and defense weaponry. Early designs done by Montresor incorporated weaponry such as cannons, mortars, and howitzers. All of them were either developed during the fifteenth century or saw significant improvements during this time to facilitate their use and become more affective during battle. The next step in fort design was a French technique known as chevaux de fries which were sunk into the Delaware River around the fort to keep out enemy ships. This caused the ships to get stuck and became an easy target from Fort Mifflin. Excavation of a part of the fort led to the discovery of the structural components that made up the walls of the fort. Not only were the walls in the common pointed, pentagon shape as seen with European fortifications, it incorporated counterforts, bastions, ramparts, and terrepleins, all of which date back to the Renaissance and even beyond. These design techniques shaped the way America defended the Delaware as they utilized the methods to trap the enemies in vulnerable positions. This enabled a small number of American troops to hold off an even larger number of the enemy, along with their ships. A prime example of the strength in technical design of the fort shows during the 5 week battle with the British. Approximately 400 American soldiers were able to hold on for that long while being surrounded by the enemy on three sides. Despite their eventual evacuation, they held off the British long enough to allow George Washington and his troops to retreat to Valley Forge for the winter and gave time for the Americans to regroup. Even though the fort was eventually taken over, it was designed strategically for a small amount of troops to hold off enemy fleets coming up the Delaware. The techniques are outdated by today’s standards as one would never think of defending a fort in this day and age using military strategies from a couple hundred years ago as there have been rapid technological advancements. However, for Fort Mifflin, due to its location on the Delaware River, older strategies were the best way to design it and enable bombardment of enemy troops, especially since the biggest military and technological advancements at the time came mostly in the form of moving from stationary to mobile artillery. By implementing Renaissance techniques in the design of Fort Mifflin, America built one of it’s most strategically important and valuable fortifications to date.

**Bibliography**

Primary: 1. G. D. Skull. __The Montresor Journals__. New York Historical Society. 1881. pg. 414 – 418. 2. Smith, George. __History of Delaware County, Pennsylvania__. Pg 285. Secondary: 3. C. T. Iannuzzo. “The Art of Warfare.” Le Poulet Gauche. 1 January 2004. < http://www.lepg.org/warfare.htm>. 4. The Science Learning Network. “Renaissance Man.” Museum of Science. Boston. < [] >. 5. Gravett, McBride. __German Medieval Armies 1300-1500__. Osprey Publishing. Pg 16. 6. Haddock, John III. “Fort Billings: A Forgotten First.” Fort Billingsport Homeland Security Preservation Committee Newsletter. Fall 2006. Volume 2. Number 2. < http://www.fortbillingspreserve.com/newsletters/newsletter06fall.pdf>. 7. This Day in History. “British Fleet Suffers Defeat at Fort Mifflin, Pennsylvania.” American Revolution. History.com. 2008. < http://www.history.com/this-day-in- history.do?action=Article&id=51325>. 8. Launmark, Ligget. The Counterfort at Fort Mifflin. Bulletin of the Association for Preservation Technology, Vol. 11, No. 1 (1979). pp. 37-74. 9. Duffy, Christopher. __Siege Warfare__. Routledge Publishing. 1985. Pg. 29. Reference: Peter Lamb. Fort Mifflin. Olde Fort Mifflin Historical Society. 2007.  < []  .> Fort Mifflin. Origin3 Custom Web Designers.< [] >