Forts and Fortifications
Forts and Fortifications
FORTS AND FORTIFICATIONS
In the 1770s, on the eve of the American War of Independence, the colonists already had an established "heritage of war." This heritage began in 1607 with the building of protective forts by the Jamestown settlers and continued in 1634 with the fortification of Boston by the Massachusetts Bay Company. The intervening skirmishes and campaigns aimed at maintaining European domination of its colonies around the world were part of the larger Euro-American heritage of war, which reached its conclusion in the War of 1812, the end of the Napoleonic Wars.
the colonial and pre-revolutionary period
Native Americans and seventeenth-century settlers and colonists frequently surrounded their villages with palisades or stockades, interchangeable terms for protective rows of felled trees dug vertically into the ground. Musketeers and bowmen shot from ports or loopholes in the stockade or, occasionally, from a blockhouse or a bastion located on one or more corners (salients) of the square or rectangular fort. Some blockhouses and bastions were two stories in height for greater visibility and firepower. Buildings for cooking, eating, and sanitation and for storage of weapons, munitions, and food, as well as barracks, were protected within the palisade when space permitted.
During the French and Indian War (1756–1763), the colonists' opposition was a Western European nation with the capability for cannon and artillery and two centuries of experience and knowledge in the military arts. Thus the colonists' level of military technology took a necessary leap. Colonial fortifications became more complex than the simple palisaded outpost, incorporating earthworks based on European military models. Fortifications, such as those at Fort Stanwix in New York colony, were frequently strengthened several times. Dirt was added, or "thrown up," behind the palisade or stockade, resulting in an earthen rampart that provided a heavier shield of protection against a besieging force. Colonists employed a "balanced job" construction technique, with the thrown-up dirt forming a ditch (or fosse) encircling the entire palisade; occasionally this ditch was filled with water to form a moat. Palisades with loopholes for firing en embrasure (from openings in the parapet) or with castellated parapets for firing en barbette (from a protected platform) were sometimes dug into the top of the rampart, adding height and visibility to the fort's firepower. In these cases, a banquette (an elevated way along the inside of a parapet) or terreplein (a level space behind a parapet) was formed for placement of defenders and cannons at a raised level. In some cases the wooden palisade was laid back at an angle on the earthen rampart, forming a revetment on the front slope of the rampart and above the scarp of the ditch. When cannonballs exploded on timber revetments, secondary projectiles of large wooden splinters were sometimes launched at both the attackers and the defenders. Trees were felled and bushes were cleared from the slopes surrounding a fort to provide better visibility; the products of this clearing activity were used to build additional elements of defensive works, including fascines (bound bundles of sticks), chandeliers (pairs of x-shaped sawhorses connected by a bar that supported fascines), fraises (long, pointed stakes projecting from the rampart at an angle) and abatis (obstacles formed by felled trees with sharpened branches).
the revolutionary period through 1794
The term "fort" had a broad meaning in the North American colonies. It referred to stockades, palisades, blockhouses, redoubts, redans (v-shaped projections from a fortified line), detached works, rifle and artillery batteries, flèches (detached v-shaped defensive works in an open field), garrisons, outposts or camps, and even castles and fortresses. A fortified place, whether a log cabin with loopholes for rifles or a huge stone castle with a hundred or more guns in casemates (protected enclosures), went by the name "fort."
Generally, American Revolutionary War forts were temporary, hasty, and pragmatic earthworks set up to respond to a perceived military threat. These early earthworks contrasted sharply with the planned and permanent castles, forts, and walled cities of Europe based on British and French siege craft theory. European fortified places were considered Enlightenment works of art, like landscaped gardens; they served as physical symbols of man's rationality and his dominance over natural forces. European manuals described the fort-building process in great
detail, relying on geometry to provide lines of fire along all angles of the fort's curtain walls so as to prevent an enemy from climbing and breaching the defensive works.
Depending on the topographic and strategic situations, forts could be triangular (fleches, outer works, and detached batteries), square, rectangular, pentagonal, hexagonal, or star-shaped. There were almost as many shapes as there were practicing military engineers and architects. But the French and the British schools clearly dominated the stately art of siege craft. The dominance of French terms in naming parts of forts (many English words derive from these imported French terms) reflects the importance of the French militarists, especially Sébastien de Vauban (1633–1707).
In the North American colonies and the early republic through the War of 1812, the star fort was preferred for political and military reasons. Because the French preferred the star and the revolutionaries were politically allied with France, it quickly became the American favorite. Strategically, the star allowed 360-degree visibility across the open glacis and beyond. Each projection of the star fort was called a salient, and the point where two salients joined, near the central body of the star, was called a re-entrant angle. The star shape enabled enfilading fire, meaning that both faces of each salient could be covered by cannons and muskets from the face of the adjacent salient. The star's salient had faces looking toward the enemy as did a bastion, but no inward-facing flanks, the absence of which meant one less surface to protect with enfilading fire. The traces of star forts were probably easier to mark on the ground during construction than other polygons that included bastions. The six-pointed "Washington Star" forts were symmetrical and stylistically compatible with Georgian and Enlightenment ideals of balance and symmetry. In addition, the American Revolutionary forces preferred to place their earthworks on hilltops, a topographic situation favoring the panoptic, 360-degree views afforded by the star. By contrast, the British preferred to locate their fortifications to enable the control of roads; thus British forts required views of only 90 degrees to either side. Given that
preference, the British had little use for the star form and little understanding of the American preference.
During the Revolution and later, Americans also commonly used linear, temporary, semitransportable breastwork constructions. These constructions, arranged linearly along a position, included gabions (baskets or cages filled with rocks used to build supports) and chandeliers that supported fascines. Such constructions snaked across the landscape at Valley Forge and Bunker Hill. They had right-angled projections, prototypical bastions, along their length, allowing the defenders enfilading fire along the face of the breastwork. These fieldworks derive historically from Vauban's system of parallels and approaches used by the besieging forces.
Just as the plan of a single fort was geometric, so was the arrangement of forts on the landscape. At Yorktown the British entrenchments consisted of two parallel arcs, with the first-built outer works set up to impede Allied forces (the combined American colonials and French) and the subsequently built inner works to protect the town itself. The outer works incorporated the naturally swampy ravines adjacent to the York River into the entrenchment plan as a means of further impeding the Allied investments. The arc of the outer work was also continued in the shallow waters of the York River when the British scuttled twenty-nine ships.
The inner, main works was planned to consist of eight redoubts interspersed by eight land batteries and four water batteries, with several picket redans, traverses, and a hornwork. These works, together with an earth-backed, stockaded line without a ditch, were arranged concentrically around Yorktown. The powder magazine at Redoubt No. 4 had a fascine-type floor and a roof covered with fascines, dirt, and rawhide that were typical of the period.
Southern coastal fortifications displayed some variability in construction materials. As a rare half-bastioned redoubt, Fort Dorchester in South Carolina was simpler to construct than full bastions but was weaker because of its fewer flanks; moreover, the faces of the half-bastions could only be protected by enfilading fire from one side. Among the earliest southern campaign fortifications (c. 1775), it had tabby ramparts walls that were an amazing thirty-four feet thick and only the customary seven to eight feet high. Tabby was a building material composed of ground oyster shells, lime, and sand mixed with salt water. Other revolutionary forts in the southeastern United States, such as Fort Frederica in coastal Georgia, were constructed of tabby.
Fort Moultrie, part of a complex defensive works that Americans collectively called Charleston, was instrumental in the early colonial victory, preceding the Declaration of Independence, of 28 June 1776. The fort's ramparts were revetted with soft palmetto log cribwork filled with artillery-absorbing sand. Enclosed bunkers located beneath the cannon on the rampart were used as magazines, officers' quarters, or a casemated lower tier of cannon. Later versions of these bomb proofs were complete with chimneys for ventilation. Fort Moultrie was an unusual Revolutionary citadel because it was the colonial counterpart of a European walled city, serving to surround a town and its civilian inhabitants.
In the southern backcountry, troubled relations between the Cherokees and Creeks, the colonial settlers, and the British resulted in the building of many fortifications between the 1750s and 1800. For example, Fort Ninety-Six was originally built by the British in 1759 as a stockade against the Cherokees, whose resistance was broken in 1761. The British used sandbags to raise the parapets by three feet and to shape the musket loopholes in the palisade. To occupy a fortification was to be on the defensive and to engage in passive practices; the British defenders waited, played games, drilled, and maintained fortifications, provisions, and equipment.
At Fort Ninety-Six in June 1781, the colonials, commanded by Lt. Col. Thaddeus Kosciusko, a skilled military engineer, unsuccessfully besieged the improved, British-held star and circular redoubts. The colonials attacked with sandbags, hooks, and ladders through almost a half-mile of excavated, underground features such as systems of parallels, approaches, saps, and mines. Aboveground, gabions served to protect the besieging colonials. The act of besieging required invaders to dig parallels and approaches in the dirt and build fascines and gabions, dissipating the strength of their offensive. A colonial innovation, the thirty-foot-high Mahan Tower topped with parapets for attacking colonial musket fire, offered a panoptic elevation to the planar landscape. The tower was built of green logs so the British hot shot would not ignite it. The British abandoned their fortifications in July 1781 because of their poor, isolated backcountry position; the War of Independence began to focus on the coasts and river near Yorktown. The Americans occupied the fortifications and used them as backcountry defenses against the British-allied Creeks and Cherokees for the rest of the eighteenth century and through their removal in the 1830s.
In the western backcountry of Appalachia, the Great Lakes region, and beyond to the Mississippi River, the colonial campaigns of 1778 and 1779 sought to break the British-Indian alliances. A string of earthen outposts and wooden stockades were built along the Ohio River system to protect the waterways that brought supplies and militia to the far western theater of operations. Fort Duquesne (renamed Pitt when under English control) is the most famous of these riverine forts, which also included Forts MacIntosh, Fincastle (Henry), and Randolph. The colonial populace frequently fled to these forts for refuge from, and retaliation against, British-inspired Indian attacks. Between 1784 and 1790 Indians killed or captured some fifteen hundred settlers in Kentucky alone. Many forts were captured by the British-Indian alliance. These forts, according to the terms of the Jay Treaty of 1794, were to be evacuated by the British by 1796.
the first system, 1794–1801
After the Treaty of Paris ended the War of Independence in 1783, Americans were concerned that France and Britain would exploit the loyalty of Native American groups to block American westerly expansion. Also, the young American nation saw Britain's nautical mercantilism and France's Anglophobia as a threat to American rights of shipping and commerce on the high seas.
In response to these threats, the fledgling federal government instituted the First American System for the defense of its seacoast from British attack. As part of this system, in 1794 the government authorized $76,000 in federal funds for the construction of coastal fortifications designed to protect fourteen geographically isolated seaports along the Atlantic Ocean from Maine to Georgia. The original authorization included another $96,000 for armaments of the forts. The design of these defenses was not American but rather largely the product of French engineer-consultants. The small funding allocations of the First System generally allowed only for impermanent, earthen fortifications that could be easily thrown up without central planning. Some First System forts were revetted with stone.
Revolutionary battles frequently had two parallel command structures: a militarist held the overall command while an engineer was in charge of building the earthen defensive forts and excavating the offensive siege works (saps and mines, for example) for the attackers. An engineer, when present, or the military leaders commanded the sappers and miners. On 16 March 1802, Congress authorized the organization of an engineer corps, known as the Army Corps of Engineers, and the institution of a military academy at West Point, New York.
the second system, 1807–1814
A renewed need for seacoast protection against the French, British, and Native Americans resulted in the Second American System of fortification of the seacoast, one of the first projects undertaken by the Army Corps of Engineers. Most Second System seacoast forts were essentially completed by 1812. Multitiered architecture, with casemates at the levels of both the parade and the terreplein, first appeared in what Americans called the castles, such as Castle Clinton in New York City, of this Second American System. The Second System fortifications were generally intended to be masonry, although local exigencies and funding may have kept some of them as backcountry earthworks. The Second System was centralized and coordinated at the federal level, with much less variability in form and method of construction than in the first. Local funding and volunteer assistance by state and other institutions, as at Dorchester Heights in South Boston, augmented the generous $3 million federal allocation. A total of thirty-one new or rebuilt forts were part of this Second System and included defenses on the Gulf of Mexico. The works of many First System forts were improved during the Second System. When the War of 1812 broke out, every town of any magnitude on the coast was protected by at least one battery. Built in 1814, Fort Gratiot, located on Lake Huron on the American-Canadian border, is an example of American palisaded earthworks that were commonly found throughout the backcountry of the western frontier.
the florida frontier, 1817–1842
Diverse groups of Native Americans including Yamasees, Muscogulees, Seminoles, Cherokees, and Creeks settled in Florida throughout the eighteenth and early nineteenth centuries. The First Seminole War (1817–1818) involved raids, with the quasi approval of the president, by General Andrew Jackson's army against the forts and crops of Seminoles, "Seminole Negroes" (Africans enslaved by the Seminoles), and escaped slaves near and on the Florida panhandle. The U.S. government followed a civilization program in this period to contain the excessive land requirements of the Native mixed economies. Conflicts with white and Spanish settlers led to a reservation north of Tampa in inland areas established by the 1823 Treaty of Moultrie Creek (near St. Augustine) with the U.S. Government. Slave raiders attacked Creek and Seminole towns to recover escaped slaves and Seminole Negroes. Florida thus became caught up in the sectional contentions over slavery. Because of these land conflicts and slave raids, Americans felt that settlers needed protection; Cantonment Brooke (built in 1824 in modern Tampa) and Fort King (established in 1827 near Ocala) were established immediately after the treaty.
After the Native American groups learned of the new governmental policy of Indian removal of 1830, the Second Seminole War (1835–1842) erupted. Seminoles led by Osceola ambushed U.S. Army troops, led by General Wiley Thompson, outside the Fort King gate. Major Francis Dade's troops were attacked en route to Fort King from the U.S. Army headquarters at Cantonment Brooke. Fort King was a palisaded outpost with two full, square, two-story bastions on opposing corners. The palisade enclosed a magazine, a two-story blockhouse, and quarters for officers and enlisted men. Other settlers' buildings located close to the palisade enjoyed the protection that the fortified garrison afforded. Fort King was abandoned in 1843 after the Second Seminole War ended.
See alsoAmerican Indians: American Indian Removal; Charleston; French and Indian War, Battles and Diplomacy; Frontier; Gunpowder, Munitions, and Weapons (Military); Military Technology; Revolution: Military History; Seminole Wars; War of 1812; Yorktown, Battle of .
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James W. Mueller