Seacoast Fortification - Third System
In 1816, the Board on Fortifications was established under the leadership of a French fortification expert of the Napoleonic Wars, Simon Bernard, to advise on defense policy and recommend modem projects in the light of recent wartime lessons. Sometimes called the Bernard Board, the establishment of this body of officers marked the nation's first permanent institution devoted to codifying a strategic doctrine and building the infrastructure of a unified defense network.
The system of fortifications that evolved from the work of the Board of Engineers in the period from 1816 to 1860 was the most comprehensive, most uniform, and most advanced the nation had yet had. The third system rationally assigned priorities for a work program to fortify numerous strategic sites. This program is best represented by large brick or stone forts with multiple tiers of gun batteries, in some cases three and four tiers high, built on promontories and on islands at choke points to important harbor entrances. It was among the principal forts of the Third System, however, that some of the most spectacular harbor defense structures to come out of any era of military architecture wereto be found. Included by virtue of their role in the Civil War were certainly some of the most famous - Sumter, Pulaski, Monroe, Pickens, Morgan and Jackson.
How completely this board studied the military needs of the country can be appreciated only by reading the reports it made at different times during its existence. They are interesting. They cover not only the military history of the period but also contain important data on the development of the country, beginning at a time when the population of the United States was only about 8,000,000 and ending in the 1860's when a population of over 31,000,000 had been reached. First and foremost, the entire coastline was studied; each harbor of importance, both for naval and commercial traffic, was considered in the utmost detail. Next, the means of manning each fortification in time of war was planned; each fort was designed to carry a peace-time garrison for its maintenance, with the method arranged for by which it could be fully garrisoned in time of war.
Fort Monroe, for example, was to contain a peace-time garrison of 600 men; in war-time its garrison was to be increased to 2,625; when first designed its armament was to consist of 380 guns of various types, but was later enlarged to contain 412 guns. Fort Pulaski was to be garrisoned in time of peace by one company (about 300 men), but in time of war it was to contain 800 men and 150 guns. Fort Morgan, Alabama, was to contain in time of peace one company, but in time of war, 700 men.
The next problem was to provide communications between the various defensive posts in dependent of naval support. To do this roads had to be built, and the following system was recommended: "The interior communications desired by the government were macadamized roads; one from Washington City, along the Atlantic coast to New Orleans; another between the same points, but running by the way of Knoxville; another from New Orleans, by way of Tennessee and Kentucky, to Buffalo and Lake Brie; and a fourth from Cumberland to St. Louis." These, with ordinary roads of the country, it was believed would facilitate adequately the inland transportation of troops and supplies in the event of war, taking care of both the land fortifications and naval depots on the several water frontiers.
From the technical standpoint, this large group of massive, vertical-walled forts represented the general embodiment and the fullest development of features which had previously appeared in only a few and isolated instances, i.e., structural durability, a high concentration of armament, and enormous overall firepower. The forts were armed by specialized seacoast artillery of relatively standardized type: it was the beginning of standardized armament systems for U.S. coast defense artillery. They incorporated defensive innovations, such as improved firing embrasures which allowed a great deal of lateral traverse from a smaller, iron-shuttered opening. The sites protected the nation's most vital naval bases, commercial ports and strategic anchorages. When these installations were completed the United States had a true system of coast defense for the first time: it encompassed all three coasts, and it was second to none in the world.
The tactical rationale behind this proposal (commonly referred to as the Plan of 1850) was to guard chokepoints with batteries close to water level in order to bring grazing fire from opposite flanks to bearsimultaneously on vessels attempting to run past. Such fire was particularly effective for two reasons. First,vessels could not hug the far shore of a channel in order to increase their distance from the defenses withoutbringing themselves nearer to fire from the opposite direction. Second, grazing fire was more accuratebecause flat trajectory fire, skipping along the water surface, had only to be accurate in deflection and not inrange. Since attacking vessels obviously benefited by exposing themselves to fire as briefly as possible, localconditions encouraged a full speed dash with both the strong incoming tide and the prevailing northwest winds combining to boost effective speed past the defenses.
The outbreak of the Civil War and rapid technological advances of the industrial revolution put the thirdsystem fortifications to severe test. Their strategic locations placed them in the forefront of numerous crucial battles of the next four years, from the first guns at Fort Sumter, to the siege of Fort Pulaski, the running of the guns at New Orleans and Mobile Bay, and the stand at Fort Fisher. Steam propulsion,ironclad warships, and rifled cannon combined to spell finis to the predominance of thick masonry wallsand expensive permanent fortifications in lieu of more flexible, repairable and cheaper earthworks, which, paradoxically, better absorbed the shock of repeated hammering from large-caliber smoothbore and rifled siege artillery.
The development of the coastal forts system relied heavily on the efforts of both military and merchant shipping. Construction alone entailed the movement of massive amounts of materials and men, with the inevitable losses that occur with bad weather and perilous navigation. At Dry Tortugas National Park there are several documented "construction" wrecks, and others are expected to be located. This will probably prove to be the case in other coastal system-related parks in the Southeast, such as Fort Sumter National Monument and Fort Pulaski National Monument, as well as Forts Pickens, McRae, and Massachusetts in Gulf Islands National Seashore, where construction and supply vessels wrecked or foundered.
Of the more than thirty forts of the third system, begun after 1816, nearly all remain extant, and althougha number have been partially altered by the superimposition of later works, the majority in their originalform constitute the oldest surviving body of major military structures in the United States.
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