Rediscovering Charleston's Colonial Fortifications

Pedestrians strolling past the swanky restaurants on Charleston’s upper King Street and promenading through the Farmers’ Market in Marion Square probably have no idea they’re treading through the heavily-fortified siege lines that once defined one of the most important battles of the American Revolution. A relatively new historical marker on the east side of King Street in the square commemorates the protracted British siege of Charleston in the spring of 1780, but it’s a minuscule reminder of a much larger scene that requires a lot of imagination to visualize. So, where were the siege lines of that historic battle, and what sorts of fortifications did the opposing forces erect? Two hundred and thirty-four years after the siege, the answers to these questions have been obscured by generations of development, but recent investigations are beginning to make the scene a bit clearer.

First, it is important to state that anyone interested in this topic should begin by reading Carl Borick’s book, A Gallant Defense: The Siege of Charleston, 1780 (University of South Carolina Press, 2003). This book provides excellent descriptions and analysis of the battle, based entirely on primary source material, and guides the reader through the many months of turmoil and bloodshed leading to the American surrender of Charleston on 12 May 1780. Mr. Borick’s book does not include a detailed analysis of the fortifications, however, because such an investigation would have derailed his book from its larger theme.

Working towards my own book on the urban fortifications of early Charleston, however, I’ve spent a lot of time gathering fragmentary details about these fortifications from surviving archival resources and the accounts of various eye witnesses to the siege. In addition, I’ve acquired copies of several manuscript maps of the era 1775–1783 that provide visual clues that help elucidate the documentary evidence. There are still more historical documents and maps out there, but locating them and obtaining copies often takes time. Nevertheless, a variety of manuscript maps from archives such as the British Library, the National Archives of the United Kingdom, the Clements Library at the University of Michigan, the Huntington Library in California, Dartmouth University Library, the Library of Congress, the South Carolina Historical Society, and of course the South Carolina Department of Archives and History, depict various parts of the suburban battlefield that is now part of urban Charleston.

Taken together, these maps illustrate, with a reasonable degree of uniformity, the many layers of fortifications employed by both sides. The American defensive lines stretched across the peninsula from the Ashley to the Cooper River, standing in ranks of graduated height from an artificial canal between John and Ann Streets to the mighty Horn Work with its back against the town limit (Boundary Street, now Calhoun Street). After sailing up the rivers and disembarking on the northern “neck” of the peninsula, the British army crept southward and encamped beyond the range of the American guns. At the beginning of April 1780, they began digging a series of siege trenches or “parallels” that zig-zagged southward from Columbus Street to the Americans’ artificial canal between John and Ann Streets. By the time British and Hessian troops drained the canal and penetrated the American defensive lines, just south of the modern intersection of King and John Streets, the end of the siege was a foregone conclusion.

Col. de Cambray’s “Plan de la ville de Charlestown” at the Library of Congress

Most of the aforementioned maps are covered by copyrights held by their respective institutions, and a sense of scholastic respect prevents me from posting them on this website. I will, however, direct readers to a very interesting French map held by the Library of Congress that is available online and downloadable. The manuscript map in question is not signed or dated, but it appears to be the work of Colonel Louis Antoine Jean Baptiste de Cambray-Digny (1751–1822), a French engineer who served in the American army in Pennsylvania, New Jersey, Maryland, North Carolina, and Georgia before being captured by the British in Charleston in 1780. Col. de Cambray, as he was known to the South Carolina legislature in Charleston, superintended the American fortifications during the siege, and the map held at the Library of Congress includes his two-paragraph caption (in French, naturellement) that gives a wonderful description of the siege and the American fortifications. A later copy of this map (with a much abbreviated caption) was published by George W. Williams in the South Carolina Historical Magazine in April 1975 (see my bibliography), but the map at the Library of Congress includes valuable, unpublished information about the fortifications. I encourage you to click on the image of the map above and read Col. de Cambray’s caption. If you need a bit of help, here’s my translation:

­Plan of the town of Charlestown of its retrenchments and of the siege made by the English in 1780.

The night of the first of April they opened their trenches. The 10th they summoned the town [to surrender]. The 13th the 1st parallel and its batteries were finished, and began to cannonade. The 18th the 2nd parallel was finished. The 24th the besiegers mad­e a sortie to the extreme right of the 3rd parallel. The 8th of May they summoned the town to surrender. The 3rd parallel and its batteries were completed and commenced a demolishing fire [“á battre en brêche”]. The 11th they made a sap very close to the salient angle of the advance battery on the left, ­and made a passage through the advance moat from which the water had been previously drained. The 13th [sic, the 12th] the town capitulated.

The retrenchments [i.e., defensive lines] of Charlestown consisted of detached redans and curtains, the parapets 7 feet high, 16 feet thick; the moat was 12 feet deep and 26 wide. It was double palisaded, there were three rows of wells [“puits,” or trous-de-loup] beyond and some strong abatis; the contested ground [“le front attaquée,” i.e., the space between the two armies] was covered by a moat full of water 30 feet wide. The retrenchments were made in haste in less than 4 weeks in 1779, and saved the town from invasion by the English under Gen. Prevost. When the English disembarked on Johns Island there were only 200 men in garrison in the town; there was not a single cannon mounted, the abatis had been burned during the winter and had not yet been remade. When the English began their entrenchments, the garrison was about 1200 men, the militia and the sailors did nothing during the whole siege the defense was always directed by Continental troops which extended from one river to the other. During the siege the English shot 10,000 bombs 16,000 bullets and 150 carcasses. The defenders were reduced to live on nothing but rice and molasses for 4 days before the town capitulated. The garrison amounted at that time numbered 1900 [illegible] including sick, injured, servants etc. The English had at the time of the reduction 13,000 men, perfectly enveloping the town by sea and by land, and could [illegble] with success to land in the town which the defenders had guarded so vigorously.

The published diaries and memoirs of several other participants in the 1780 siege of Charleston, including those of Henry Clinton, Banastre Tarleton, Johann Hinrichs, Johann Ewald, and William Moultrie, provide additional details that help us imagine the scene. Walking around the environs of Charleston’s King Street and Marion Square, however, the modern built environment makes it difficult to visualize the battlefield of 1780. I’m in the process of attempting to overlay historic maps onto recent satellite images of Charleston, and this endeavor can prove to be very illuminating. If you’d like to see those overlays and learn more about the siege of 1780, please join me for a program titled:

“Charleston’s Fortifications of the

American Revolution, 1775–1783″

Wednesday, November 19th 2014 at 6:00 p.m.

Second Floor Classroom, Charleston County Public Library, 68 Calhoun St., 29401.