~Introductory Remarks ~

Fort Jackson also called "Old Fort Jackson" and "Fort James Jackson" to distinguish it from all the other Forts Jackson (masonry and modern) was constructed from 1808 to 1812 as a second system river defense fortification capable of sustaining a land attack of short duration. Its primary purpose was to oppose a hostile fleet ascending the Savannah River with the intention of either bombarding the city or landing an army to attack and occupy the place. With this object in mind Fort Jackson was designed to oppose the passage of a hostile fleet by engaging it with heavy sea coast artillery mounted and elevated well above the river's high water mark on a six face open water battery while defending against a land attack from an irregular quadrilateral demi-bastioned masonry enclosure that was crenellated for small arms defense and embrasured for light artillery on the flanks of the demi-bastions.

Defense of the fort was supplemented by a revetted wet ditch that was fed by water drawn from the Savannah River through a tide tunnel; the wet ditch combined with the height of the crenellated walls (approximately 22 feet) would have effectually prevented any attempt to capture the work by escalade and compelled an attacking force to erect siege batteries and batter one or more breaches in the scarp wall before an assault could take place. Ground in the immediate vicinity of the fort was generally level and cut into rice fields that would have materially impeded any assault and created certain challenges in the construction of breaching batteries. Since the crenellated walls were not covered by a glacis breaching operations could be conducted at ranges up to 1,000 to 1,200 yards using heavy smoothbore siege artillery and at much longer ranges by rifled artillery. Rifled artillery positioned near Causten's Bluff or McQueen's Island (slightly over one mile and two miles distant) combined with heavy siege mortars would have been able to breach the landside scarp walls and attack the free standing powder magazine and rear of the casemates to compel a capitulation in a matter of hours once the batteries of the attack had been completed.

Fort Jackson's position on the river was favorable to a good land defense at the time of its original construction, but was primarily selected to fulfill its role as a river defense fortification. An earthwork fortification had been constructed at Fort Jackson's location to defend Savannah during the War of 1812; the position itself was suggested by the fact that the British fleet that attacked Savannah in 1779 disembarked its land force near the fort's position prior to its successful advance against the city. It would have been difficult to improve upon the fort's position to increase its ability to resist an attacking fleet. Fort Jackson was located at the narrowest point in the river between the confluence of the Front and Back Rivers upstream and the separation of the Savannah River into its north and south channels at Elba Island. The position was also the farthest point from the city that could not be taken in reverse by an advance using the network of creeks and streams to the east and south. Although the fort looked out over one of the deepest points in the river its site provided every advantage to the defense that nature could offer between Savannah and the sea.

As a second system fortification the design and construction of Fort Jackson was the work of a single engineer or successive series of engineers whose work was not subject to review by a board of experienced engineers. It was an individual effort and bears the mark of the guiding engineer's experience or inexperience, his talent for the task or lack of talent and foresight in turning the natural advantages of the selected site to good account within the limits imposed by budgetary restraints. Given the fort's primary object of opposing a hostile fleet it appears from the structure itself that rather too much attention and expense was concentrated on the design and construction of the water battery. The water battery wall was traced with six faces and five salient angles with the longest face enabling the work to engage enemy ships as they sailed upstream toward the fort; two faces engaged the river immediately in front of the front and one other would insure that any ships attempted to pass the work could be taken stern on as they headed toward the city. Short faces at either end of the trace prevented ships from hugging the river bank to engage the opposite ends of the water battery with reverse fire. Unlike third system masonry fortifications that depended upon a single wall to shelter the work from enemy fire, Fort Jackson's engineer designed a thick masonry enclosure packed with earth fill that did nothing more than support the water battery's parapet and close the end of the battery's casemates. Concentric arched vaulting of the cramped casemates supported the water battery's terre-plein in rear of the interior enclosure wall and provide the space needed to mount the fort's designed armament of 14 heavy sea coast guns. The masonry enclosure create a double wall effect; a hostile fleet finding it desirable to breach the water battery wall would be required to breach two walls and blast away the earth fill between them to open the interior of the fort to its close and direct fire. Given the fact that shell guns were hardly an artillerist's dream at the time when the fort was constructed, the double wall imparted an extra measure of protection to the interior of the work that no fleet, it was probably hoped, could reasonably challenge.

~ Exterior Views ~

~ Interior Views ~

~ Loop-Holes ~

~ Demi-Bastions ~

~ Maps and Charts ~

Detail from Map Illustrating the Defence of Savannah, GA. and the Operations Resulting in Its Capture by the Army Commanded by Maj. Genl. W. T. Sherman. (1880-81)

Detail from Preliminary Chart of Savannah River Georgia (1855)

~ Internet Resources ~

Coastal Heritage Society Old Fort Jackson

Quantum Tours Tour of Old Fort Jackson