Selected Papers From The 1983 And 1984 George Rogers Clark Trans-Appalachian Frontier History Conferences (2024)

GEORGE ROGERS CLARKSelected Papers From The 1983 And 1984 George RogersClark Trans-Appalachian Frontier History Conferences

Fortifications on the Eastern American frontier havelong been a subject of interest to historians — but until recentlythe study of forts has primarily been the domain of antiquarians whoseknowledge and understanding of military architecture was limited towhatever local sources and traditions were apparent for a particularfort site. For the serious student of military architecture there is awealth of resources on frontier fortifications: documentary resourcesfor specific structures, including the correspondence of fortcommandants and travelers' observations; information on contemporaryfortifications built by the same individuals; and general eighteenthcentury fortification theory.

This paper proposes to examine these sources toreveal the large variety of options available to the military engineeron the eastern North American frontier during the 18th and early 19thcenturies. What principles for example, applied to the construction offrontier forts? How were these principles employed in the actualconstruction of a primary fort element such as the walls? How did thebackground of various fort builders influence the design of specificforts?

A starting point for the study of any frontierfortification is with an understanding of the general architectural andtheoretical background of European military thought. While it is truethat these tenets were modified in America, this was the intellectualbaggage brought into the frontier by practically every officer.

European architects and engineers of the 15th centurywere faced with the introduction of gunpowder into the warfare of thewestern hemisphere. This technological advance altered forever thecharacter of fortification design. Most immediately it made thetraditional stone castle fortification obsolete. Tall stone walls weretoo easily reduced to rubble by an attacker's artillery. The bastionedsystem of fortification was developed in Italy in the 15th century inresponse to this new armament. [1] When viewed with historicalperspective, the fortification developed by the Italians to solve thisproblem was striking in its simplicity: they lowered the whole complexdown into the ground. To prevent an enemy from simply walking into thelowered fort, the old moat was retained and developed into an elaborateditch system. A portion of the dirt from the ditch was thrown to thefront to create an earthen slope called a glacis. This aided in hidingthe fortification and supposedly provided an absorbing cushion forcannon balls fired by an attacker's artillery or at least harmlesslydeflected them. The new fortifications became a "defense in depth" inplace of the former emphasis on height. In conjunction with thispassive defensive system, a more aggressive method of defense focusedaround the corner projections known as bastions. From these corneremplacements the troops and artillery of the defenders could bring crossfires upon the attackers outside the fort walls. The round towers commonto medieval castles were problematic because they resulted in anundefensible area at their base. The simplest solution was to point thestructure and various arrangements on the corners and walls weredesigned to cover the entire exterior ground of the fort within acertain distance. As a result European fortifications of the 16th, 17thand 18th centuries consisted of remarkably complex series of angles andplanes, and an understanding of geometry and adeptness at drawing werethe tools of the military engineer's trade. [2] The term bastioncame from the French word for fortress, and very quickly the bastionbecame the prime characteristic of virtually all Europeanfortifications.

The Parts of a Fort. (FromAlfred Proctor James and Charles Morse Stotz, Drum in theForest, ©Historical Society of Western Pennsylvania,1958.)

Originally the Italians were the leadingpractitioners of this new bastioned system, but by the 17th century theFrench acquired a continental reputation for their impressivefortifications. Most prominent among the French military men wasSebastien Le Prestre de Vauban who served as an engineer in Louis XIV'scourt. Vauban had a reputation of never surrendering a fort and neverhaving failed to take one attacked. In fact it was through his offensiveprowess that he made his major accomplishments. Volumes written by himand published in the early 18th century became the standard referenceworks in the field consulted by military leaders of all nationalities.Subsequent authors borrowed heavily from Vauban's concepts in a sizablearray of books on fortification theory and practice. [3] Mostincluded elaborate illustrations that reflected the high development ofthe bastioned system in Europe. These publications were carried to NorthAmerica by military officers assigned to the colonies and weretranslated and adopted by the new United States.

On the American frontier few fortifications reachedthe sophistication of these European models. William Smith's volume onthe Henry Bouquet expedition into Ohio in 1764 contained an outline ofthe basic principles for forts on the American frontier entitled"Construction of Forts against Indians." The appearance of the outlinein manuscript form accompanying some Ohio Valley fort plats in thecollections of the Indiana Historical Society attest to its use in theMidwest. It reads in part [4]:

"As we have not to guard here against Cannon, thesystem of European Fortifications may be laid aside, as expensive, andnot answering the purpose. Forts against Indians, being commonly remotefrom our settlements, require a great deal of room to lodge a sufficientquantity of Stores and provisions, and at the same time ought to bedefensible with one half of their compleat Garrisons, in case ofdetachments or Convoys."

In this statement we can see three basicconsiderations that should be kept in mind when studying frontierfortifications. First was the public concern, whether it was French,British, or American, for limiting the expense of frontier forts. Theclaims of frugality made in the correspondence of fort commandants weresurpassed only by their superiors' demands for the same. Secondly, thesefrontier forts were designed principally to house and provide for themovement of stores and supplies. Finally, they had to be defensible by asmall quantity of troops.

Another vital concept for what the 18th centurymilitary officer termed as "field works" a contemporary term for what wetoday would call frontier fortifications, was put forward by a Frenchengineer named Clairac who wrote a volume entitled the FieldEngineer which was translated and published in Philadelphia in1776. [5] George Washington had a copy of this work in his own personallibrary. The concept stated that any soldier defending a fortificationgenerally fires mechanically straight ahead rather than to the right ofleft.

How was this concept manifested in a specificfrontier fort? Lines of musket fire can be projected at right anglesfrom the walls on the plat of Fort Duquesne, built in the middle of the18th century at present-day Pittsburgh. A cross fire is brought on thearea directly in front of the main walls of the fort from firing stepson these walls and from the flanks of the bastions. A larger area iscovered from the faces of the bastions. But what of the ground oppositethe points or salient angles of the bastions? Since the area wasuncovered, ravelins or simple pointed projections were erected in thecenters of each wall. Lines of fire from the faces of the ravelinscovered the ground before the bastion angles. At Duquesne this wasnecessary on only two sides, since the Ohio and Monongahela Riversprotected the other sides of the fort and made assault from thesedirections unlikely. [6]

Following the tenets of Smith's book, Clairac'sconcept of "lines of fire" and the components of the bastioned systemitself did not dictate a single form for frontier fortifications. Theoutline of the French Fort Duquesne which we examined earlier can beviewed as the "typical" bastioned fort in the frontier. A variation onthat trace was the "half-bastion" or demi-basion shown in the plat ofFort Lernoult built by the British at Detroit in 1778. Henry Bird, theengineer for this fort, acknowledged that this trace was less perfectthan full bastions, since more area was uncovered on the exterior of thewalls. But the open configuration of half-bastions allowed for increasedstorage space on the interior. More importantly the reduced number offaces and flanks on the bastions made them simpler and quicker toconstruct and thus less expensive. [7]

The star trace used by the British to build Fort Bullin western New York in 1755 departed even more from the bastioned systemby omitting corner emplacements entirely and utilizing "redan" ortriangular type structures in the center of each wall. As in theprevious example the reduced number of walls lowered the cost and alsoresulted in a need for fewer garrison troops. In this case it did notwork to the advantage of the defenders for French forces captured anddestroyed the fort a few months after it was built. [8] The starshape left many areas outside the fort uncovered, but according to oneBritish military writer in the 1780s it was a popular form withAmericans at the start of the Revolution, especially since it supposedlywas invented by and remained a favorite of the French who assumed therole of military tutors for the new nation. [9]

Military engineers considered the triangular formeven less desirable, since it left uncovered with any field of firesignificant segments of the area outside the fort. Still it was usefulin situations where there were very small garrisons and a shortage oftime or money to build a more sophisticated structure. Such was the caseat the Pickaway Indian towns near the modern city of Springfield, Ohio,in 1780. Henry Bird, builder of Fort Lernoult, reportedly directed theconstruction of a triangular stockade and blockhouse at thesesettlements. A structure with a minimum of walls was optimal in asituation where the discipline and capabilities of the defending troopswas limited. [10]

Civilian fortifications, particularly blockhouses,became the norm on the Old Northwest frontier during the War of 1812,because by this time there were a number of substantial areas ofsettlement. While European military treatises were noticeably silent onthe subject, there are many contemporary accounts and drawings ofblockhouses, both military and civilian, which describe two-storywooden structures, often but not always, with the second storyprojecting over the first. [11] A number of these early 19thcentury military structures are still standing in the northern UnitedStates and [12] even more remarkable is the preservation of acivilian blockhouse in Miami County, Ohio, several miles east of Troy.It has perhaps escaped notice in the past because its construction doesnot fall into the traditional images of a frontier blockhouse. It couldperhaps be better classified as a fortified house; it is a two-storyresidence built of two-foot-thick stone walls. A masonry first story forblockhouses was actually not rare on the frontier, and was, in fact,recommended by some British military officers to increase the durabilityof a blockhouse and again reduce its long term expense [13]. TheMiami County blockhouse was built in 1813 and actually was much moreresidential in character than military in its overall design andfinishes. One major element of the original design was unmistakablymilitary: the inclusion of a kingpost truss in the attic which withwrought iron tie rods supported the load of the second-story floorjoists and thus eliminated the need for load bearing walls on the firstfloor. The open lower story, uninterrupted by walls and with cornerfireplaces, was ideal for defensive militaryactivities. [14]

We have seen how the basic fortification conceptsdeveloped in Europe were adapted in the American frontier. Taking this astep further, a close examination of one particular structural elementwill build an appreciation of the design choices available to themilitary engineer in the late 18th and early 19th centuries in NorthAmerica, and aid in understanding the exchange and interaction ofmilitary ideas on the frontier. The most basic architectural element ofan eastern frontier fort was its wall, and there was, in fact, a greatvariety of construction techniques and devices, so it is perfect forthis type of survey.

By far the most common fort wall was the stockade.Contemporary civilian accounts of frontier fort construction like thatdirected by Ben Franklin in 1756 are replete with descriptions of thistype of fortification. [15] It was, of course, ideally suited tothe capabilities of a non-military force requiring no special skillsbeyond an adeptness with an axe and shovel. [16] While itprovided a certain sense of security, a single wall stockade was aflawed system. In the first place a single row of logs with one endstuck in the ground produced a highly unstable structure, even with thestandard ribband or strip of wood connecting each picket, so that itconstantly required attention to provide any defense at all. Secondly,unless great care was taken in selecting the logs and placing them inthe trench, there were frequently significant gaps between each log.

Military officers, therefore, insisted on either"lining" the walls with boards to cover the gaps or to add a second rowof smaller pickets inside the first row and positioned between the outerrow to cover the gaps. By the early 19th century this latter method hadbecome the standard in the fortification classes taught by the U.S.Military Academy at West Point. [17]

The French Fort Maurepas from the late 17th centuryin the lower Mississippi Valley was clearly built by an insecurecolonial power to guard against the incursions of the British. The wallsin this case were constructed by the French commandant as a double rowof large logs supplemented by a smaller row to the rear. In other words,it was triple stockade intended to defend against lightartillery. [18]

An interesting variation to increase the stability ofthe stockade was designed by British engineers at Fort George in 1799.Here every 14th picket was planted several feet further into the groundthan the adjacent pickets and was strengthened with a brace ofhorizontal and diagonal members at its base. [19]

Another simpler variation on the "standard" stockadewall was used in Fort Necessity, Pennsylvania, constructed by Virginiamilitia under the direction of George Washington in 1754. The walls ofWashington's odd little circular fort were composed of oak logs split inhalf with smaller posts on the interior to serve as musket rests or tosimply fill gaps in the wall. The archaeologist who discovered thisdesign for the National Park Service in the 1930s speculated that thiswall may have been unique to Washington and a result of time andpersonnel shortages during its construction to reduce the quantity oftrees that had to be felled. It should be noted, however, that this samewall design was still being used in the southern states 80 years later,so that this technique may, in fact, represent a regionalcharacteristic. [20]

Vertical stockade walls could also be combined with"traditional horizontal log wall building construction to form the outerwall of the fortification. In other words the rear walls of the fortbuildings also served as the outside wall of the fort and pickets wereused to fill between the buildings. This was a common feature ofcivilian fortifications or "stations," but was also used in militaryforts where time constraints were a factor. Such was the case at FortJefferson built in 1791 during Arthur St. Clair's ill-fated campaign,only in this case a horizontal log wall construction was utilized forthe corner bastions as well. [21]

Perhaps the simplest of all frontier fort walls werethose erected by the U.S. Army and Kentucky militia in the Ohio Valleyduring the 1790s. These "temporary fortifications" were formed bycutting down trees to form a 5-foot high breastwork which oneparticipant called a "brush fence." Occasionally where timber was scarcethe walls were formed of earth, but it was done on a daily basis toprotect the encamped army from surprise attack. [22]

All of the wall systems were only a defense againstthe limited armament of Indians and not a European enemy equipped withartillery. To defend against the latter type of attack required a moresophisticated structure intended to absorb the shock of artillery.

Fort Defiance was originally built in modern-dayDefiance, Ohio, by the U.S. Army in 1794. It initially had a stockadewall set in a 3-foot trench. Following the Battle of Fallen Timbers andthe confrontation with the British fort at present-day Maumee (FortMiamis), the Army returned to Defiance and began modifying it to accountfor a European enemy. Archaeological excavations done several summersago show the distinctive profile of a ditch dug out around the perimeterof the fort and thrown against the wall. [23]

Most horizontal log walls were actually composed oftwo parallel walls tied together with cross member to form a crib-workand then filled with earth. This system could be used by itself to formthe walls of a fort, as at the British designed Fort Ligonier built in1758; or it might be combined with heavy wooden buildings immediately tothe interior which were themselves covered with earth as protectionagainst artillery as at Fort Ontario also built by the British in thelate 1750s. [24] Both techniques were intended as a defenseagainst artillery, but since each relied predominantely on wooden formsthey were still susceptible to artillery. As a consequence when theenemy was primarily a European one, earthen fortification walls werepreferred.

During the 18th century a clear distinction was madeby military theorists between regular and irregular fortifications.Regular fortifications technically referred to a work whose defensivestructures were all symmetrical and had equal components. there isevidence to suggest, however, that the term regular fortification had anadditional meaning to military officers in America. Anthony Wayne, forexample, referred to a regular fortification as one defensible againstartillery. [25]

To construct an earthen wall fort a wooden frameworkwas prepared under the direction of the engineer. It served nostructural function, but rather simply marked the limits of the parapetas a guide for workmen. The dirt for the outer ditch was then dug outand thrown into the framework. As the U.S. Military Academy at WestPoint developed its programs, officers were trained to calculate thetime involved in erecting such a structure by determining how far anindividual could throw the earth, and at what rate, depending on thesize of the final wall desired. [26]

The earth was unstable by itself and required somephysical support to maintain its shape. Sod, cut in slabs and laid likebrick was one method of providing a cohesive revetment; in anothermethod the earth was secured with fascines (bundles of sticks); orhurdles (a type of interwoven basketweave frame); or gabion (wovenbaskets filled with earth), or a scrap revetment formed of dovetailedplanks or heavy timber or stone slabs like at Fort Wayne in Detroit. Allwere covered in detail for officers at the U.S. Military Academy in theearly 19th century. [27]

What then can we learn from the study of frontierforts? The first point to make is that too often the concept of frontierfortifications has been vastly oversimplified by historians and anassumption made that one fort was pretty much like another. Even thetreatment of forts on the Cis-Mississippi frontier in Willard Robinson'srecent book American Forts is relatively cursory and lightweight.As I have tried to indicate, military architecture holds the samepotential for information as the study of building types and styledistributions normally associated with folklorists and architecturalhistorians. A whole host of various plans, materials, techniques andfunctions governed 18th and 19th century fort design decisions. Studyingthe interplay of these elements as displayed in frontier forts can shedlight on the spread and adaptation of cultural characteristics betweendifferent peoples. What, if any, techniques for example, were unique tothe Dutch, French, Spanish, or British engineers who built forts in theAmerican frontier?

Any purely architectural study of course runs therisk of treating structures in an abstract manner separate from theirhuman environment and perspectives. In recognition of this, I have triedto focus on specific individuals when discussing particular forts toemphasize that each was designed through a series of personal decisionsbased on knowledge, training or experience. There are any number ofindividual engineers, superintendents of construction and masterbuilder/carpenters who were recognized as "experts" in their field andwhose assistance was frequently solicited on new fortifications.

One brief example will demonstrate the validity ofthis latter approach. William Ferguson was an Irish immigrant whosettled in Pennsylvania in the 18th century and enlisted in theContinental Artillery during the Revolution. When the small federal armywas created in the 1780s he obtained a captain's commission in theartillery and served at a number of posts in the Ohio Valley. As anartillery officer, Ferguson was frequently called on to provideengineering services for the army, a typical practice of the period.After he was promoted to Major and assigned to Arthur St. Clair'sill-fated army in 1791, he in effect, became chief field engineer on theexpedition, responsible for directing the construction of allfortifications. One of the posts Ferguson served at prior to theexpedition was Fort Finney at the falls of the Ohio River. One of itsdistinctive features was a guardhouse positioned in the center of thewall opposite the main gate which projected out from the wall. It shouldcome as no surprise that when Fort Hamilton was built under Ferguson'sdirection it included a guardhouse placed exactly as that at FortFinney. An examination of groups of forts erected by and under theguidance of individuals like Ferguson, much as architectural historianshave looked at the work of a particular architect, is yet another usefularea of study. [28]

The field of military architecture is, therefore, alargely unexplored and promising area for future research.

Conjectural Plan of Fort Hamilton, ca. 1793

NOTES

¹Sebastien Le Prestre de Vauban, AManual of Siegecraft and Fortification (1740), translation andintroduction by George Rothrock (Ann Arbor: University of MichiganPress, 1968), pp. 3-4. The introduction written by Rothrock has ageneral discussion of the advent of the bastioned system. For a morein-depth discussion see John R. Hale, "The Early Development of theBastion: An Italian Chronology, c. 1450-c. 1534," in Europe in theLate Middle Ages (London: Faber and Faber, 1965), pp. 466-494. Seealso Charles M. Stotz, "Defense in the Wilderness" in Drums in theForest (Pittsburgh: Historical Society of Western Pennsylvania,1958), pp. 59-197.

²Americans who observed the Frenchengineers operating during the Yorktown campaign in 1781 made note oftheir "geometrical operations." See James Thomas Flexner, GeorgeWashington in the American Revolution (Boston: Little, Brown, &Co., 1967), p. 435.

³Vauban, Manual of Siegecraft andFortification, pp. vi-xi.

⁴William Smith, An Historical Accountof the Expedition Against the Ohio Indians in the Year 1764(Philadelphia: William Bradford, 1765); and "Construction of Fortsagainst Indians," Northwest Territory Collection, Indiana HistoricalSociety.

⁵Chevalier de Clairac, L'Ingenier DeCampagne or, Field Engineers, (translated by Major LewisNicola) (Philadelphia: R. Aitken, 1776); Richard Ketchum, The Worldof George Washington (New York: American Heritage, Inc., 1974).

⁶Stotz, "Defense in the Wilderness,"opposite p. 129.

⁷Willard B. Robinson, American Forts:Architectural Form and Function (Urbana: University of IllinoisPress, 1977), pp. 56-57.

⁸Gilbert Hagerty, "Fort Bull: APre-Archaeological Study, Northeast Historical Archaeology, Vol.2, No. 1 (Spring 1972), pp. 20-21.

⁹Lochee, Elements of FieldFortification (London: author, 1783), p. 61. An illustration of astar fort is in Captain George Smith, An Universal MilitaryDictionary (London: J. Millan, 1779), p. 95.

¹⁰"Account of Henry Wilson" in J. MartinWest, ed., Clark's Shawnee Campaign of 1780 (Springfield: TheClark County Historical Society, 1975), pp. 32-37; "British Account ofBird's Expedition," Draper Mss, State Historical Society of Wisconsin,Madison, 29J19. Interestingly there are some indications that theIndians were more "disciplined" than might ordinarily have been thecase. One participant reported their forming into a line of battle andadvancing as a group against Clark's troops.

¹¹Two European travelers' accounts whichdescribe blockhouses are Francis Bailey, Journal of a Tour inUnsettled Parts of North America in 1796 to 1797 (London: BaileyBros., 1856), p. 145; and Isaac Weld, Travels Through the States ofNorth America, and the Provinces of Upper and Lower Canada, During theYears 1795, 1796, and 1797 (London: John Stockdale, 1807), Vol. II,pp. 178-179. Perhaps the best known drawing was in Thomas Anburey,Travels Through the Interior Parts of America (London, 1789). Theblockhouses built by the U.S. Army at Fort Fayette at Pittsburgh in 1792were built with the second story equal in size to the first story, sinceaccording to Isaac Craig projecting upper stories resulted in "veryInsubstantial Buildings." See Craig to Henry Knox, January 15, 1792,Letterbook II-A, Isaac Craig Collection, Carnegie Library ofPittsburgh.

¹²Two examples are the Americanblockhouses at Fort Mackinac on Mackinac Island, Michigan, built between1798 and 1800, and the West Point Blockhouse at St. Andrews in NewBrunswick built in 1812. An especially useful description of Britishblockhouses in Canada is Richard J. Young, "Blockhouses in Canada,1749-1841: A Comparative Report and Catalogue," Canadian HistoricSites: Occasional Papers in Archaeology and History, No. 23 (Ottawa:Parks Canada, 1980), pp. 5-116.

¹³See Patrick Sinclair correspondence inBrian L. Dunnigan, "The Post of Mackinac, 1779-1812" (M. A. thesis,Coopertown, N.Y., 1976), pp. 56-57.

¹⁴This was similar to the old StateArsenal built in Columbus, Ohio, during the Civil War and the barracksat Fort Wayne in Detroit dating to 1848. See National Register ofHistoric Places Inventory and Nomination Form for the John Minor DyeStonehouse, Troy Vicinity, Miami County, in the Ohio HistoricPreservation Office, Columbus. A "fortified house" in Pennsylvania wassimilar in design to the Dye blockhouse. See James W. Van Stone,"Fortified Houses in Western Pennsylvania," PennsylvaniaArchaeologist, Vol. XX, No. 1-2 (Jan.-June 1950), p. 23.

¹⁵Thomas Lynch Montgomery, ed., Reportof the Commission to Locate the Site of the Frontier Forts ofPennsylvania (Harrisburg: Wm. S. Ray, 1916), pp. 190-194; William A.Hunter, Forts on the Pennsylvania Frontier, 1753-1758(Harrisburg: Pennsylvania Historical and Museum Commission, 1960), pp.236-7.

¹⁶The concept of a palisade was, onefortification treatise indicated, "ancient even in ancient times" andthus had a long European precedent. See Lochee, FieldFortification, p. 25.

¹⁷C. Meigs, "Notes on Course of FieldFortification," Joseph M. Toner Collection, Box 267, Figure 18th,Library of Congress.

¹⁸Robinson, American Forts, pp. 24,26.

¹⁹Robert S. Allen, "A History of FortGeorge, Upper Canada," Canadian Historic Sites: Occasional Papers inArchaeology and History, No. 11, pp. 65-66.

²⁰J. C. Harrington, New Light onWashington's Fort Necessity (Richmond, Va.: Eastern National Park andMonument Assoc., 1957), pp. 38-42; James R. Hinds and Edmund Fitzgerald,"Fortifications in the Field and on the Frontier," PeriodicalVol. IX, No. 1 (Spring 1977), pp. 48-49.

²¹David A. Simmons, The Forts ofAnthony Wayne (Fort Wayne, Ind: Historic Fort Wayne, 1977), pp.10-11.

²²Anthony Wayne to David Strong, May 29,1793, Wayne Papers, Historical Society of Pennsylvania, Vo. 26, p. 124;"General Orders for the Volunteers," September 4, 1794, Wayne Papers,Presbyterian Historical Society, Philadelphia; Dwight L. Smith, ed.,From Greene Ville to Fallen Timbers: A Journal of the Wayne Campaign,July 28 - September 14, 1794, Indiana Historical SocietyPublication, Vol. 16, No. 3 (1952), p. 250; Entry for September 18,1794, Diary, Jonathon Taylor Papers, Filson Club, Louisville, Ky.

²³Simmons, Forts of Wayne, pp.15-18; Interview, Ronald Burdick, Defiance College, Defiance, Ohio.

²⁴Charles M. Stotz, "The Reconstruction ofFort Ligonier: The Anatomy of a Frontier Fort," Bulletin of theAssociation for Preservation Technology, Vol. VI, No. 4(1974), p.63; Robinson, American Forts, p. 41.

²⁵Simmons, Forts of Wayne, pp. 19,26.

²⁶Civil War era drawing is an excellentresource showing this type of activity. David H. Donald, ed., Gonefor a Soldier: The Civil War Memoirs of Private Alfred Bellard,(Boston: Little, Brown & Co., 1975), p. 164; Meigs, "Notes on FieldFortification."

²⁷H. Mahan, A Complete Treatise onField Fortification (New York: Wiley and Long, 1836), pp. 53-60.

²⁸Heitman, Historical Register andDictionary of the United States Army. (Washington, D.C.: GovernmentPrinting Office, 1903), Vol. 1, 417; David A. Simmons, "Fort Hamilton,1791-1797; Its Life and Architecture" (M.A. Thesis, Miami University,1975), pp. 3, 14.