Civil War Forts in Arlington

Civil War Forts in Arlington

Union defenses in Arlington during the Civil War

An overview of Union forts in Arlington

C.B. Rose, Jr.

Arlington Historical Magazine

Arlington Historical Society

1960

Public Domain

Civil War Forts in Arlington
By C. B. RosE, JR.

When the fall of Fort Sumter on April 14, 186!, made it clear that an armed struggle between North and South could be avoided no longer, it was obvious that the City of Washington would be in a difficult position. There was little doubt that Virginia would follow her southern sister States and secede from the Union. Thus a hostile shore would face the Northern Capital, which lacked any strong natural defenses. For political as well as military reasons it was of prime importance to the Federal Government to secure its capital from attack. Since the Executive Mansion and many Government buildings were exposed to artillery fire from the heights on the Virginia side of the Potomac, it was essential to retain that commanding position in Federal hands.

Arlington Heights in turn had to be protected from attack. This entailed the construction south of the Potomac of an elaborate system of defenses, most of which lay within what is now Arlington County. Alexandria was seized by Northern forces partly because of its command of the Potomac and partly because of its connection with the railroad system to the south. This occupation called for a further fortification system which was not strictly
part of the defenses of Washington and which is not considered here in
detail.

In the month which intervened between the action of the Virginia Convention on secession and the ratification of this action by the people of Virginia on May 23, 1861, the only step taken by the defenders of Washington was a limited, surreptitious reconnaissance of the areas around the Virginia ends of the Aqueduct and Long Bridges. On the night of May 23- 24, however, the first Federal troops crossed the Potomac into Virginia, thus beginning for Arlington one of its most important periods historically.

Three units made the crossing: one, under Maj or Wood, crossed over the Aqueduct Bridge from Georgetown; a second, under Major (later General) Heintzelman marched over the Long Bridge; and the third, under Colonel Ellsworth, who was to be the first casualty of the war in this area, proceeded by water to Alexandria. The only opposition encountered was that of some pickets at this end of the Long Bridge ( where the Railroad Bridge crosses
now) who were overcome without any casualties. General Mansfield, the commanding officer of the occupying forces, established his headquarters at Arlington House on the heights overlooking Washington.

The immediate task was to secure the crossings. Capt. D. P. Woodbury assisted by Lt. 0. E. Cross was in charge of engineering operations for the NoTE: This account relics heavily upon the report of Maj. Gen . J. G. Barnard on the defenses of Washington, printed as No. 20 of the "Professional Papers of the Corps of Engineers, U. S. Army" in 1871. first unit; and Capt. B. S. Alexander with Lt. F. E. Prime was the engineering officer for the second. The general sites for the first works had been determined by the pre-occupation inspections, and the troops were well supplied with entrenching tools. Work on what became Fort Corcoran overlooking the Aqueduct Bridge, and on Fort Runyon astride the important junction of
the Washington-Alexandria and the Columbia turnpikes half a mile south
of the Long Bridge; was commenced at daylight. To secure Alexandria, Fort
Ellsworth was begun on Shuter's Hill (where the Masonic Memorial is now)
on the 25th. It was named for Colonel Ellsworth, who had been killed the
previous day while removing a Confederate flag from the Marshall House
on King Street.
Both of the first two forts in Arlington lay at a lower level than Arlington
Heights and themselves required protection. Before the week was out, work
was begun on Fort Albany (now lost in the Shirley Highway network) on
the high ground to the rear of Fort Runyon, and shortly Forts Bennett
( above the old Consumers Brewery site) and Haggerty ( opposite Analostan
Island) were built to protect Fort Corcoran. Rifle trenches to guard the approaches to all these points also were dug. Work on these preliminaries took
seven weeks.
The work which had been accomplished by July 1861 was not very extensive and served rather to protect the Northern bridgeheads on this shore of
the Potomac than to effect any sort of defense of Washington. The Confederate victory at Bull Run in that month underlined the immediate necessity
for constructing a proper system of defense. The first requirement was to
fortify Arlington Heights by connecting Forts Corcoran and Albany by
intermediate works within musketry or canister range of one another. Together with Fort Runyon this chain would cover the bridges and also protect the all-important commanding heights of Arlington.
Accordingly, a number of "lunettes" were constructed. These are field
works with two faces coming together to form a salient angle, with two
parallel flanks. The rear entrance into the lunette was called a "gorge," or
throat, and was protected by stockades. These works became Forts Craig,
Tillinghast, Cass, and Woodbury. Fort Strong was constructed to protect
the right flank of the line. (Fort Strong was originally called DeKalb and
appears as such on some maps.) The first three were on or near what is now
the Fort Myer reservation; Fort Strong was out Lee Highway near what is
now North Adams Street; Fort Woodbury was on Court House hill. Captains Woodbury and Alexander were responsible for the location and design
of these works.
Wide slashings were made through the forest in advance of the line of
these works, and marginal slashings were made around their edges. Halfsunk batteries for field guns were prepared between the sites of Forts Strong,
Woodbury, and Craig. These were not armed but were arranged so that field
pieces could be placed in them on short notice.
Attention was now directed to the wooded ridge north of and parallel to
the lower course of Four Mile Run which offered a position from which
Washington, the Long Bridge, and the plateau in front of it could be overlooked and cannonaded. The first step was to make access to this point difficult by cutting down about 200 acres of trees. These were left where they
fell; the stumps were tall enough to impede cavalry without offering cover
to infantry. As soon as the proper site could be determined, a large lunette
(Fort Scott, now near a County playground) was built upon it. Later, this
was thrown to the rear of the line of defenses by the extension of the system
to Alexandria and beyond, but together with Forts Richardson and Craig
and the rest of the first chain it completed the line independently of the
Alexandria forts.
Fort Richardson (on what is now the Army-Navy Country Club grounds)
was begun on September r, r86r, as a small polygonal work after General
Richardson's division holding a position along Columbia Pike pointed out
the importance of commanding the plateau along which this road passed.
The turnpike was a major communication route with the heights 4 miles
west from Arlington House, first occupied by McDowell when he was marshaling his forces to move on Manassas. Subsequently, this was an advance
position of the Confederates, who withdrew in October r86r. It was not until
then that this area was fortified by McClellan with the construction of Fort
Ramsay and Fort Buffalo ( on either side of the Leesburg Pike near Seven
Corners) and an encampment made on Munson's Hill. A cavalry picket supported by a few companies of infantry thenceforth occupied this point.
The first idea of the Northern engineers was to connect Forts Ellsworth
and Scott by works along the ridge on which Mount Ida is situated (above
Russell Road in Alexandria), but it was discovered that this was not practical
since this line could be overlooked. Accordingly, on September r, Forts
Worth and Ward were begun. Fort Reynolds (above Shirlington; first called
Fort Blencker) was built as part of this line. Later Fort Barnard was added
to fill in the gap between Forts Reynolds and Richardson.
As important as securing the heights and the bridgeheads was the necessity
for protecting the roads which gave access to these points. One of the most
important of these, since it was a main communication link with the Federal
forces in northern Virginia, was the Georgetown-Leesburg road running
west from Chain Bridge. Moreover, it was vital to protect the bridge itself
from artillery fire. At an early date, some sketchy defensive measures had
been taken at Chain Bridge. A barricade was placed over the first pier from
the Virginia side, with a movable staircase so that a defending force could
retreat over the flat below, leaving the bridge open to the fire of two mountain howitzers which were placed on the District end. A battery ("Martin
Scott") consisting of one 8-inch seacoast howitzer and two 32-pounders was
placed on the palisade above. Since this could be overlooked from the Virginia side, later a second battery ("Vermont") was installed at a higher level
to support the first.
On September 24, 1861, Gen. W. F. Smith's division crossed Chain Bridge
and began the construction of Forts Marcy and Ethan Allen. Both were finished in a few weeks. While these could be overlooked from Hall's Hill a
mile and a half away, it was not considered practical to extend the defense
of the bridge that far. Eight unarmed batteries were constructed for field
guns to sweep the valley of Pimmit Run. A strong stockade with a gate later
was thrown across the road to Leesburg.
By the close of 1861, there were 23 forts south of the Potomac, including
those in Alexandria. The largest of these ( and, indeed, of all the forts surrounding Washington) was Fort Runyon with a perimeter of 1,500 yards.
Most of these were enclosed works of earth, but many, as has been mentioned, were lunettes with stockaded gorges. The armament was mainly 24-
and 32-pounders on seacoast carriages, with a few 24-pound siege guns, rifled
Parrott guns, and guns of light caliber on field carriages. The magazines
were provided with 100 rounds of ammunition for each gun, and a few of
the works had bomb-proofs in which about one-third of the garrison might
sleep and in which all could take temporary shelter.
While the result of the First Battle of Bull Run had stimulated feverish
activity in strengthening the defenses of Washington, later military developments-the successes of Grant in the West and of Dupont at Port Royalinduced a feeling of apathy. This went so far that an Act of Congress early
in 1862 appropriating $150,000 for completing these defenses specified that
none of this money was to be spent for beginning new work. Those responsible for the security of the city, however, knew that the defenses were not a
thoroughly fortified line and that the line as it was was too loosely constructed to repel raids.
Public sentiment was again aroused after the failure of the Federal forces
to take Richmond in September 1862 and the retreat of the Union Army toward the Capital. Maj . Gen. J. G. Barnard was placed in charge of the engineering operations in this area, and at once he took energetic means to
strengthen the line by construction and improvement. His review of the situation produced a number of recommendations. The ravines and depressions
between forts should be controlled by auxiliary batteries, and the works connected in a way which would both protect the defending troops and offer
obstacles to the passage of an attacking force. A change had to be made in
the character and arrangement of the armament: the heavy 24- and 32-pounders on barbette carriages were unmanageable and exposed. They were to be
replaced by light guns on field or siege carriages in embrasures, that is, an
opening in the parapet with sides flaring outward. Moreover, rifled 100-
pounders should be mounted at intervals of 2 or 3 miles to provide flanking
foe.
It was obvious that the expenditure required for these improvements
would be considerable, yet Secretary of War Stanton authorized the work to
proceed even in the face of the recent congressional restriction upon the use
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of funds for this purpose. To support his position and justify a request for
additional appropriations, Stanton appointed a commission on October 25,
1862, to "examine and report upon a plan of the present forts and sufficiency
of the present system of defenses for the city." Members of this commission
were Brevet Brig. Gen. J. G. Totten, Brig. Gen. M. C. Meigs, Brig. Gen.
W. F. Barry, Brig. Gen. J. G. Barnard, and Brig. Gen. G. W. Collum.
Altogether at that time 1 surrounding W ashington were 53 forts and 22
batteries, armed with 643 guns and 75 mortars. There were about 25,000 infantry troops which provided two men for every yard of the perimeter, supported by one man in the rear. A rtillerymen numbered about 9,000, which
gave three reliefs for each gun, and there were 3,0::io cavalry for outpost duty.
At the extreme left of the line, below Alexandria, was Fort Lyon on
the heights south of Great Hunting Creek. Fort Ellsworth commanded
Alexandria and the railroad station ( not the present one). Cooper's Hill
commanded the deep ravine behind Fort Worth and the commission recommended that a work be placed upon it. This became Fort Williams. Moving up the line, next come Forts W orth and Ward before Arlington County
is reached.
The first fort in the County was Fort Reynolds, placed to command the
valley of Four Mile Run. Since it had no view of the approach from the
west, the commission recommended that a seven-gun battery be constructed
200 yards west of the Fort. This was done and named Battery Garesche.
Further recommendations which were carried out were to obstruct the valley
of Four Mile Run with "abatis" (felled trees the sharpened ends of whose
branches face the enemy) and to continue the line of rifle trenches across
the valley.
Across Four Mile Run, Fort Barnard occupied a naturally strong position,
covering the head of a ravine in which large bodies of troops could be collected in preparation for a fl ank attack upon any force assaulting the lines
between it and Fort Craig, or attempting to penetrate the valley of Four
Mile Run. The commission did not consider any of the works up to this
point part of the real defenses of Washington, commenting: "To defend
Washington on this side, requires simply that the enemy shall be kept at
such a distance from the banks of the Potomac that he cannot shell the city.
This object is accomplished by the chain of works from Fort Scott to Fort
Dekalb (Strong), resting its fl anks on the Potomac, the left near Four Mile
Run, and the right opposite Georgetown."
Fort Scott, then, fo rmed the left of the proper defenses of Washington.
Next came Fort Richardson, occupying a very commanding position. While
small, it was well built, well armed, and amply provided with bomb-proofs
and magazines. At the time of the inspection, a rifled 100-pounder was being
placed there to sweep the sector from Fort Ellsworth to Fort Strong.
1 At the close of the war there were 68 enclosed forts and batteries surrounding Washington
with emplacements for r , I 2 0 guns. There were 35,71 r yards of rifle trenches, and three blockhouses.
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Fort Albany the comm1ss10n found partly bastioned, well built, and in
good condition. The parapets were turfed and the "scarps" (the face of the
ditch below the parapet) "revetted"-that is, lined-with boards. It was well
defiladed and in a good position to cover the Long Bridge and look into the
"gorges" of Forts Richardson and Craig. It "saw" the high ground in front
of Fort Tillinghast and commanded the valley between Forts Richardson
and Scott.
By this time (the fall of 1862) Fort Runyon no longer had the importance
that it had had at first; it had been allowed to deteriorate and had been disarmed. The commission recommended that, as a bridgehead, it should be
rearmed and reconditioned. "Fort" Jackson, immediately at the bridge end
on the Virginia shore, hardly deserved the name. It was little more than an
outpost for pickets of a small force stationed at the District end of the Bridge.
The five works-Forts Craig, Tillinghast, Cass, Woodbury, and Strongextended the line from Forts Richardson and Albany to the Potomac opposite Georgetown and covered the heights of Arlington. The commission
commented that the line would have been better had it been thrown half a
mile farther forward-that is, away from the Potomac-than it had been, but
found that the line where it was was by no means unfavorable, and stated
that it was "not so much an error of judgment as a necessity of the circumstances under which it was built." This was a reference both to the haste
with which the sites of the forts had been selected, and construction begun
when the first occupation forces entered in r86r, and to the army engineers'
ignorance of the topography of this area, close though it was to the Nation's
Capital.
The commission appraised the system of defense in Arlington in the following fashion:
The line south of Fort Richardson, either by magnitude or commanding position of
works, or both, has great strength ; if broken, the enemy has yet another line to carry
before he can reach the bridges or the heights opposite Washington. If, advancing by
the Columbia turnpike, he attempts the left flank of the Arlington defenses, he takes
a line of attack through comparatively low ground, swept to a greater or less degree by
cross or front fires from Forts Ward, Blencker [Reynolds], Barnard, Richardson, Craig,
Tillinghast, and Albany. The route from Ball's Cross Roads, approaching the center
and right flank of the Arlington lines, is, from the configuration of the ground, not
this closely swept and commanded. It forms the most practicable approach, and it leads
most directly to the point to be gained. All the ground in front, to the distance of a
mile, is, however, swept in fiank by the mo-pounders and other rifled guns of Fort Richardson and of Batteries Cameron and Parrott [ on the District side of the river], at an
extreme range of two miles, and from the rifled roo-pounders at Fort Ward and the
two mo-pounders of Battery Kemble [across the river], at an extreme range of three
and one-third miles, while it is under the direct fire, to a distance of at least 1,000
yards, of the works, closely contiguous to each other, of the line.
The commission did make some recommendations for improvements.
These were: a work at the "Red House," later built and called Fort C. F.
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Smith, to strengthen the extreme Bank of the line on the Potomac and enfilade the long and deep ravine on the right and in front of Fort Strong; a
work on the spur behind Forts Cass and Tillinghast (later built and called
Fort Whipple-now Fort Myer) to "see" into the gorges of these works and
give important fire upon the high ground in front of the line, and Bank that
line from Fort Woodbury to Fort Strong. This would also strengthen Fort
Corcoran. The commission also recommended the construction of additional
batteries for field guns and more bomb-proofs in the forts and strengthening
the bridgehead at the Aqueduct Bridge.
These recommendations were carried out in the early part of 1863, and
Forts Whipple and C. F . Smith constructed at that time have been characterized as "the most perfect and beautiful specimens of what may be called
'semipermanent' field works." It was in 1863 also that Fort Berry, an unBanked work of moderate dimensions, was built at an intermediate point
between Forts Barnard and Richardson. It was connected to the latter by a
line of trenches. Fort Morton, between Fort Woodbury and Fort Strong,
was converted from an open battery to an enclosed fortification.
While the commission did not consider the works at the Chain Bridge
part of the defenses of Washington, it did inspect them and reported that the
position was strong and well occupied. The lines of rifle trenches which connected Fort Ethan Allen and Fort Marcy with each other and with the banks
of the river, together with the auxiliary batteries, were well placed to defend
the ravines. Should these works fall, they would come under the fire of the
heavy guns of Batteries Cameron, Parrott, Kemble, and Vermont and of
Forts Alexander and Franklin on the District side of the river.
After this period, the only work undertaken on the fortifications in Arlington was in the nature of repair and improvement of existing structures, and
the commencement of construction of Fort McPherson behind Fort Craig in
1864. Intended to be a second Fort Whipple, this fort was not completed before the end of the war.
A summary description of the system of defenses when brought to its
greatest strength goes far to explain why this area was never actually penetrated by the Confederate forces-the only real attempt was by Early in the
summer of 1864 and that was against a portion of the line in the Districtand did not even prove tempting to guerrilla groups such as those under
Mosby operating nearby.
Thus from a few isolated works covering bridges or commanding a few especially
important points, was developed a connected system of fortifications by which every
prominent point, at intervals of 800 to r,ooo ya rds, was occupied by an inclosed fieldfort, every important approach or depression of ground, unseen from the forts, swept
by a battery for field guns, and the whole con nected by rifle trenches which were in
fact lines of infantry parapet, furnishing employment for two ranks of men and affording covered communications along the line, while roads were opened wherever necessary so that troops and artillery could be moved rapidly from one point of the immense
periphery to another, or under cover, from point to point along the line.
2I
The woods which prevailed along many parts of the line were cleared for a mile or
two in front of the works, the counterscarps of which were surrounded by abattis.
Bomb-proofs were provided in nearly all of the forts; all guns not solely intended for
distant fire, placed in embrasure and well traversed; secure and well-ventilated magazines, ample to contain roo rounds per gun, constructed ... All commanding points
on which an enemy would be likely to concentrate artillery to overpower that of one
or more of our forts or batteries were subjected not only to the fires, direct and cross,
of many points along the line, but also from heavy rifled guns from distant points unattainable by the enemy's field gun s. 2
CONSTRUCTION DETAILS
The forts were constructed with a slanting parapet, 7 to 9 feet high, with
an exterior slope of 45 ° . The thickness of the parapet ran from 8 to 12 feet
except on exposed fronts where the minimum was 12 feet increasing to 18
feet. A ditch, usually 6 feet deep, was dug at the foot of the pa rapet. In the
early construction a berm, or walk, of 18 inches was left between the foot of
the parapet and the edge of the ditch, but weather damage after the first
winter caused these to be abandoned, and then a uniform slope of 45 ° from
the exterior crest of the parapet to the bottom of the ditch was adopted. In
most cases these exterior slopes were sodded, and those so treated were still
in perfect condition at the close of the war.
The face of the ditch next to the parapet is called a "scarp" and the opposite face a "counterscarp." The "glacis" or slope away from the counterscarp
was raised enough to bring the ground in front of the works within the line
of rifle fire from the parapets, and on it was laid an abatis extending around
the whole fort. On the interior of the parapet, called a "breast-height," a sort
of platform known as a "banquette" was constructed on which infantry could
stand to fire.
In the beginning, the interior earth slopes were revetted, that is, faced,
with ordinary boards. This construction proved to be very perishable. When
suitable timber in sufficient quantities could be obtained, a revetment of vertical posts was generally adopted. Such posts were 4 to 6 inches in diameter,
and of oak, chestnut, or cedar, cut into lengths of 5 ¼ feet and set in a slope
of six in one in close contact in a trench 2 feet deep at the foot of the breastheight. These were sawed off 16 inches below the crest and shaped to receive
a horizontal capping piece of 6-inch timber hewed or sawed to a half-round.
The advantage of this kind of revetment was that a shot perforating the
parapet might knock out one or two posts and cause them to rotate in a
vertical plane, but if the posts were laid hori zontally, more of the defenders
would be exposed to injury from each hit.
Vertical post revetments were sometimes applied to the scarps, but sod
revetment, though more expensive in the first instance, was preferred since
it was more durable and would yield no splinters if hit by shot. Sods cut 4
inches thick, 18 inches long, and 12 inches wide were laid grass down in
2 Barnard, op. cit., p. 33- 34.
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three courses to form a sod wall 12 inches thick. Small pegs 3/4 inch in diameter and 9 inches long were driven through each alternate course into the
layers beneath.
The "cheeks" or sidewalls of the embrasures (openings for guns) were revetted with "gabions." These were wickerwork cylinders filled with the turf
trimmings from the sod revetments. The grass soon grew and enveloped the
wickerwork, forming a durable facing even after the wicker had decayed.
In the early days, the magazines and bomb-proofs were only temporary
structures, quite inadequate for permanent forts. In improving them different methods had to be adopted for the forts north and south of the Potomac
since timber had become scarce in the latter area. This was because the forests which had originally covered much of the land had been destroyed,
partly cut down by the troops for firewood or other purposes and partly because the trees had been felled to clear the ground around the forts. Sometimes, as in the case of Fort Scott, this clearing had been carried to great
lengths. Thus in the forts south of the Potomac it was necessary to make the
walls of these interior structures of hewn timber bents, consisting of plate
and sill and posts placed at intervals of 4 feet. North of the Potomac round
timber posts were placed vertically in close contact.
The sills were hewn on the upper and lower sides only, to a thickness of
12 inches. The posts were hewn on the inside only, and to this face was
nailed the magazine lining of r ½ -inch plank. The posts were cut to lengths
of 6 feet 9 inches, with a tenon 3 inches long at each end fitting into corresponding mortises, 4 feet apart from center to center, in plate and sill. The
plate was hewn to 12 inches square. The width of the magazine was generally 12 feet as this permitted storage of powder barrels in three rows. The
roof logs were not less than 12 inches in diameter and projected about 6
inches beyond the side walls. They were notched to saddle onto the capping
of the sidewalls. The roof logs were hewn so that they would lie close
enough together to hold up the earth which was piled over them. The ends
were sawed off obliquely and against these projecting ends, inclined posts
were placed at 3-foot intervals. Behind these inclined supports a revetment
of small poles, 2 to 4 inches in diameter was placed horizontally and carried
up as the earth was replaced externally. This arrangement created an air
chamber around the magazine which, in conjunction with air ducts, provided quite thorough ventilation. Floors were laid on sleepers to allow 7 feet
of head room.
Great care was taken in the roofing to prevent percolation of water. Another row of logs was laid across the roof logs, and earth rammed into the
interstices. A course of r-inch tongue-and-groove planking was nailed to the
upper logs and painted on the under side with a caulking compound of hot
coal tar and resin boiled together. A heavier composition of coal tar, resin,
and sand was used to Bush the joints as they were driven home. The upper
side of the roofing was then painted thickly with this hot composition and a
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second course of boards laid simultaneously. Another coat of the tar composition was laid on this, on top of which 2 or 3 inches of fine clean sand
was thrown. This was followed by 2 feet of clay applied in layers of 6 to 8
inches, very thoroughly rammed. The remainder of the earth was then covered with a layer of sod.
The minimum depth of the earth covering all sides of the magazines was
ro feet. This was determined upon after experiments on the penetration of
rifled, field, and siege artillery at probable distances. It was intended that
shells should not only not reach the woodwork inside the magazines but also
not penetrate far enough to inject fire by their explosion.
Construction of bomb-proofs was similar with the exception that the rear
was open and covered by a projecting roof. Care was taken in the location
within the forts of all these interior structures to make them serve as traverses, defilading the faces of the work. They were furnished with banquettes from which infantry fire could be directed into any part of the fort
which might have been entered by an attacking force.
Gun platforms for field and siege guns were constructed as follows: a
foundation of earth was prepared by thorough ramming, at such a level that
the platform surface should not be less than 71/;2 feet below the crest of the
parapet. Planking was laid on round timber sleepers not less than 9 inches
in diameter and 18 feet long, hewn on the upper side. On these were spiked
3-inch planks, 14 feet in length, laid transversely, sloping to the rear to aid
in checking the recoil of the gun. A "hurter" or buffer, of 6-inch timber was
placed at the forward end of the platform at a distance just sufficient to keep
the wheels of the carriage clear of the revetment. An improved gun platform
was constructed in the later works. This was of hewn timber, 6 inches thick
by 10 to 14 inches wide. This hewn timber flooring was more firm and durable than planking- even the smaller field pieces like the IO-pound Parrotts
cut through the 3-inch planking after much practice. A distance of 23 feet
from center to center of platforms was adopted as the minimum. This distance gave the greatest practicable amount of artillery fire in a given length
of face consistent with the convenient working of the guns.
To give the guns the greatest possible field of fire, the embrasures were
cut to a splay of 48°, that being the maximum consistent with adequate
strength and cover at the throat. The sides, or cheeks, of the embrasures were
generally revetted with gabions.
Construction of parapets for the batteries was the same as for the forts.
Many of them were provided with magazines, and all of them with traverses.
In the case of open batteries, generally no ditch was excavated but the material for the parapet was obtained by excavating in the rear.
Nearly all the important works were provided with wells. Some of them
were very deep, as at Fort Lyon below Alexandria where it was necessary
to go down 175 feet to get water. Most of them, however, were 30 to 60 feet
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deep. The walls were curbed with brick or stone and were about 8 to ro feet
in diameter.
Three kinds of trenches were used to connect the works and form part of
the line of defense. They also served as covered ways along which troops and
even artillery might move. Construction was of a less permanent type than
in the case of the forts, with no interior revetments. Earth was thrown up
from an interior excavation so that the whole afforded a cover of some 71/2
feet. The bottom of the trench was graded to provide drainage. Trenches
intended for troops only were 5 feet wide, while those designed for the movement of artillery were 8 feet wide. Sometimes trenches were adopted for use
as gun emplacements in which case embrasures were constructed and platforms of well-compacted earth were made.
M ILITARY ROADS
The line of defensive works was readily reached by several existing County
roads, but intercommunication was not adequate-and, in the beginning, in
some cases nonexistent. The necessity for communicating roads became apparent as soon as the general line was established. The conditions governing
their location and construction were that they should not be overlooked
from any ground that an enemy might be able to occupy in front, that they
should be as direct as practicable consistent with easy grades, and that they
should be wide enough to permit the movement over them of field batteries
or army trains.
The first road of this character was constructed in the fall of 1861 for the
purpose of connecting the isolated works at Chain Bridge with the right of
the Arlington lines at Fort Strong. This road, about 3 miles long, was laid
out by Capt. B. S. Alexander, mainly through a broken and densely wooded
country. In part, it is the Military Road of today. The type of road may be
imagined when it is learned that it was built by troops who completed the
job in two or three days!
The occupation by the Army of the Potomac in the winter of r86r- 62 of
the territory from Arlington Heights to and beyond Fort Lyon (below Alexandria) caused it to be traversed by innumerable rough wagon roads, and
communication along the lines soon became practicable, although very difficult in wet weather. At a later period a route was laid out and a good road
constructed partly by details of troops and partly by hired labor. This road
ran to the rear of and communicated with all the works from Fort Strong to
Fort Lyon. Other roads were built from the Aqueduct Bridge to Forts C. F.
Smith and Strong, and from the same point to Fort Whipple and thence to
Fort Albany.
While some of these roads were in part improvement of existing roads or
lanes, others were wholly new. Some of them have been abandoned or built
over, but others, like Military Road from Glebe Road to Lee Highway, form
the basis for streets and highways in the County today.
* * * * *
It takes little imagination to picture what this occupation and the construction of this system of defense meant to Arlington County. In r86r, the
County was a rural community the people of which were largely dependent
upon farming for their livelihood. Forts thrown up right and left, trenches
dug through pastures and truck g.irdens, forests cut down, troop encampments all about-the impact of these changes must have been tremendous.
While never an actual battleground, it is probably not too much to say that
Arlington could hardly have been affected more had it been.
GLOSSARY
Abatis-A defense formed of felled trees, the sharpened ends of whose branches face
the enemy.
Banquette- Footwalk or platform on which infantry might stand on the inside of a
parapet or other earthwork, to fire.
Barbette-A mound of earth or a platform on which guns are mounted.
Breast-height-Interior face of a parapet.
Defilade-To arrange a fortification so as to protect the lines from frontal or enfilading
fire, and the in terior of the works from plunging or reverse fire.
Embrasure-An opening, with sides Baring outward, in a wall or parapet through
which cannon are fired.
Gabion-A hollow cylinder of wickerwork, filled with earth or other material and
used in building field works.
Glacis- Slope from the coun terscarp to the open country.
Lunette- A fieldwork consisting of two faces, forming a salient angle, and two parallel
Banks.
Revetment-A facing of stone, concrete, or wood, etc., to sustain an embankment; a
retaining wall.
Scarp-The side of a ditch next the parapet. The opposite side is a counterscarp.
DERIVATION OF NAMES OF FORTS IN ARLINGTON
Battery Garesche- After Lt. Col. Julius P. Garesche, Asst. Adj. Gen. of U.S.A., killed
at Murfreesboro, Tenn., December 31, 1862. Gen. Order, A.G.O. 83, 4-1-1863.
Fort Reynolds-(First called Fort Blencker.) After Maj. Gen. J. F. Reynolds, killed at
Gettysburg, Pa., July 2, 1863. Gen. Order, A.G.O. 313, 9-17-1863.
Fort Barnard-For Maj. Gen. J. G. Barnard, Colonel of Engineers in the U.S.A., in
engineering charge of the defenses of Washington for most of the period 1861-
1865.
Fort Berry- After Gen. Hiram Berry, Col. 4th Maine, killed at Chancellorsville, Va.,
May 2, 1863.
Fort Scott-For Gen. Winfield Scott, Gen. Order, A.G.O. 18, 9-30-1861.
Fort Richardson-For Gen. Israel Richardson, native of Vermont, Col. 2d Michigan,
commanding troops holding a position along Columbia Pike. Di ed of wounds at
Antietam, Md., November 3, 1862.
Fort Albany-For the capital of New York, because it was constructed by New York
troops. Gen. Order A.G.O. 18, 9-30-1861.
26
Fort Runyon-For Brig. Gen. Theodore Runyon, commanding officer of Runyon's New
Jersey Brigade. Gen. Order, A.G.O. 18, 9-30-1861.
Fort Craig- For Lt. Presley 0. Craig of Massachusetts, killed at Bull Run, July 21,
1861. Gen. Order, A.G.O. 18, 9-30-1861.
Fort Tillinghast-For Capt. Otis H. Tillinghast, killed at Bull Run, July 21, 186r. Gen.
Order, A.G.O. 18, 9-30-1861.
Fort Cass- In honor of Gen. Lewis Cass of Michigan.
Fort Whipple-For Maj. Gen. A. W. Whipple, died May 7, 1863, from wounds at
Chancellorsville.
Fort Woodbury-For Maj. D. P. "\Xfoodbury, engineering officer in charge of construction of defenses in part of this area in 1861-2. Gen. Order, A.G.O. 18, 9-30-r86 r.
Fort Morton-In honor of Gov. Oliver P. Morton of Indiana.
Fort Strong-(First named Fort DeKalb.) For Gen. George C. Strong of Vermont.
Died of wounds at Fort Wagner, Charleston Harbor, S. C., July 30, 1863. A.G.O.
354, T r-4-1863.
Fort C. F. Smith-For Maj . Gen. Charles F. Smith, died of disease at Savannah, Tenn.,
April 25, r86z.
Fort Bennett-For Capt. Michael P. Bennett, 28th New York, Gen. Order, A.G.O. r8,
9-30-1861.
Fort Corcorn n-After Col. Michael Corcoran, 69th New York. Gen. Order, A.G.O. r8,
9-30-1861.
Fort Haggerty-For Lt. Col. James Haggerty, 69th New York. Gen. Order, A.G.O. 18,
9-30-1861.
Fort Ethan Allen-For the Revolutionary hero of that name. Gen. Order, A.G.O. r8,
9-30-1 861.
Fort Marcy-For Brig. Gen. R. B. Marcy, Chief of Staff for Maj. Gen. George B. McClellan. Gen. Order, A.G.O. 18, 9-30-1861.