Historic Structure Report
HISTORIC BASE MAP: BUILDING LISTINGS
SECOND FORT AREA
The Earthwork, or Second Fort, was designed by
Captain Cuvier Grover, 10th Infantry, in mid-1861. Constructed under the
direction of Captain Grover and First Lieutenant William J. L.
Nicodemas, 11th Infantry, under the command of Major (Brevet Lieutenant
Colonel) William Chapman, 2nd Infantry (Arrott, card 63). The site was
selected about August 4, and construction began August 4 or 5 (Oliva,
"Frontier Army," p. 332). The detailed inspection of the field work
itself and the available maps and photographs by Nicholas Bleser in the
1960s, and his suggestions about the plan of the Second Fort, its
probable interior arrangement, and the locations and functions of its
outworks, all formed the basis upon which the present plan and detailed
inventory was founded. Without his research, fieldwork and insights, the
present Base Map of the Second Fort could not have been carried out.
As built, the fortification was apparently intended
to measure 490 feet along each front (the line from the point of the top
of the parapet of one salient to the next), although the actual
measurements range from 483 to 503 feet as a result of various errors.
The principal errors in the layout seems to have been a 1 degree error
in setting out the central angle (east-west angle is 91 degrees), and a
mistake in measurement that added 20 feet to the southwest corner. Each
corner should have been 346.5 feet out a diagonal, but the southwest
vertex was set at 366.5 feet instead.
Setting the point for the face angles of the bastion
worked fine, except that the midpoints were measured along the fronts
only from the northwest and southeast angles, offsetting them somewhat
because of the earlier errors. The distance of 1/8 of the front (61.25
feet) was then measured perpendicular to these assumed midpoints of the
front, and lines marked on the ground along the lines from the salients
to these points. The construction crew would then have measured a
distance of 1/3 of the front, or 163.33 feet, along these lines from
each salient. The point arrived at by this measurement was the location
of the outer corner of each flank, and the section of line between the
salient and the corner of the flank was called the face. The line from
this point at right angles to the face line from the next salient formed
the flank itself. At some point early in the construction of the
earthwork, but too far along to start over, it was realized that a
severe error had been made in the layout, so that when the flanks were
marked in their correct positions on the ground, the distance between
each two facing flanks was about 160 feet. As a result, the midpoints
were about 80 feet from the flanks, rather than the absolute minimum of
90 feet. This meant that the cannon could not be depressed far enough to
bear on the area at the center of each front.
The actual minimum size of such an earthwork is 600
feet along each face. The earthwork actually began with an outline of
630 feet on a side, a comfortable size, but this was then used as the
outer edge of the ditch, rather than as the crest of the parapet.
Grover's basic mistake, worse than the ones mentioned above concerning
the layout of the original square, was a simple error at the very
beginning of the drawing of the plan for the earthwork. Essentially, he
plotted the basic outline of the fort with faces of 630 feet, but
instead of marking the ditch outward from this line, making it the
outline of the parapets, he measured the ditch inward, making it the
outer edge of the ditch. Grover, as the designer, probably made the
decision to attempt to correct this fault by making each of the
distances from flank to midpoint 100 feet. He did so by reducing each
face to a length of 50 feet, and making the curtain (the line of parapet
between the inner corners of the flanks) 195 feet long. When this
correction was carried out on the ground, across the irregularities of
the already-existing ditches and embankments, it was marked out very
badly, so that most of the angles and distances are off in varying
amounts. This produced the plan of the earthwork as it stands today. The
fortification was declared capable of maintaining a defense as of August
26, 1861, although it underwent almost continuous further construction
work through early 1863.
Apparently everyone involved in the effort to
construct the fort kept quiet about the mistake; had it been known
outside the very few persons directly involved in the work, it would
have been loudly discussed in the same article in the Santa Fe
Republican, July 5, 1862, that scathingly made public the other
errors in its construction: it was too close to the western ridge to be
safe from fire directed from its top, and the tunnel intended to supply
water to the garrison collapsed soon after construction and was a wasted
effort, anyway, since wells begun inside the earthwork immediately found
water after the completion and collapse of the tunnel.
However, Grover wasn't through with making mistakes.
Not only the sloppy revision of the flanks and faces, but also the need
to place the enlisted barracks and the storerooms in the redans resulted
from the size error. In fact, Major Chapman himself said on August 26
that the earthwork was "not as capacious as it might have been under
other circumstances, but considering the time at which it was commenced,
the necessity for its rapid completion and the force to be employed upon
it, we have accomplished more than I expected . . ." (Arrott Collection,
card 63, Major William Chapman, commanding, Fort Union, to Colonel E. R.
S. Canby, Headquarters, Department of New Mexico, Santa Fe, August 26,
1861). Had the earthwork been built to the correct size, there would
have been enough room within the parapets for the barracks and
storerooms. By September 3, Colonel Canby had become insistent that the
stores be gotten into secure, protected storage spaces immediately. The
reduced interior space of the earthwork meant that some alternative had
to be found for these structures. The earthwork was protected by the
usual outworks in the form of earthen banks called redans or demi-lunes;
about the first week of September, 1861, Captain Grover suggested that
they be altered to contain the Company Quarters, storerooms, and
presumably the Officer's Quarters. Grover apparently prepared the design
about September 5, 1861, and Lt. Col. Chapman forwarded it to Colonel
Edward Canby, who approved it on September 19, 1861 (Canby discussed
this sequence of events in a letter from Headquarters, Department of New
Mexico, Santa Fe, to the Adjutant General of the Army, Washington, D.
C., dated July 22, 1862; the letter of approval is Canby, Headquarters,
Department of New Mexico, Santa Fe, to Lt. Col. Chapman, commanding,
Fort Union, September 19, 1861; Part I, p. 44; Oliva, "Frontier Army,"
p. 460). Construction on the barracks and storehouses in the redans was
virtually complete by October 20, 1861 (Part I, p. 44). By January 7,
1862, virtually all of the Quartermaster property, Ordnance stores, and
provisions had been moved from First Fort to Second Fort.
Unfortunately, once again Grover had miscalculated.
Lt. Alexander Robb, who inspected the earthworks in June, 1862, noted
that the change to the outworks interfered with the lines of fire from
the main earthwork, clearly because they stood too high above the
ground; the main guns could not be depressed below a certain angle, or
they would fire into the back sides of the barracks. The barracks
therefore provided cover to potential attackers.
To sum it up, this is without a doubt one of the most
poorly planned and constructed earthworks ever built: an error in the
original plan made it too small, the attempts to correct the small size
resulted in a poor plan of fire and outworks that provided cover for the
enemy rather than the defenders, and the site was chosen too close to
superior ground for the defense to be effective even if the design had
been correct. It is an obvious case of too much haste and too little
Construction on the fort was stopped on June 12,
1862. The work was under the direction of Captain John McFerran at the
time; McFerran designed Third Fort later that same year. However, in
November, 1862, a second major effort of building began, resulting in
the construction of bombproof barracks, officer's quarters, and a
magazine within the earthwork, apparently replacing non-bombproof
structures of similar use (Part I, p. 54). In March, 1867, an order came
through to demolish the remaining buildings of the second fort and
salvage the materials, except for those still being used as laundresses
housing and stables, awaiting the completion of HS-16, 23, and HS-18,
26, about 1868. Some were still in use for storage during the late fall,
Although no maps of the Second Fort as it was
designed or completed are available, one plan drawn by Lambert under the
command of Captain Henry Inman in January, 1867, shows a sketchy outline
of the eastern third of the ditches and outworks. The 1866 and 1868 maps
show a rough plan of the Fort, although these maps depict the buildings
on its interior as two rows of three structures, with no resemblance to
the layout visible in photographs taken in ca. September, 1865, or to
the traces visible today. It is possible that the layout of buildings
inside the earthwork as depicted on the 1866 and 1868 maps were taken
from the original plans of the fortification, and show the layout of the
original, non-bombproof interior structures, before the reconstruction
beginning in November, 1862. The photographs, 111-SC-88000, 88001 (FOUN
905), and 88004 (FOUN 906), National Archives, were all taken about the
same time in ca. September, 1865, probably by Farnsworth as part of his
documentation of the conditions at the time.
SECOND FORT STRUCTURES
|HS||Name and Use|
Second Fort. This number applies to the entire
circumference of the ditches and embankments. By early August, 1861, 200
men were working on each four-hour shift, and it was expected that by
mid-August it would be capable of defense (Arrott, card 62). The basic
construction was complete by the end of August, 1861 (Arrott, card 63).
The original layout of buildings on the interior of the earthwork may
have been two rows of three structures, as shown (erroneously) on the
1866 and 1868 maps. These structures were not bombproof, and were
replaced in November and December, 1862, with bombproof buildings in a
cross-shaped layout, as shown on the present plan.
By February, 1862, it was planned that the cannon
would be set in place beginning in May (Rocky Mountain News, March 18,
1862). It is possible that Colonel Paul mined the defenses and
warehouses (Oliva, "Frontier Army," p. 487 n. 178). By June, 1862, the
problems with drainage began forcing the removal of most of the stores
and many of the men from the buildings. Both the North and the South
believed that Fort Union was unassailable (Oliva, "Frontier Army," pp.
477, 480) until June, 1862, when Captain P. W. L. Plympton, 7th
Infantry, commander of the fort at the time, found that the fort was
within range of a 12-pound howitzer fired from the crest of the ridge to
the west of First Fort (Oliva, "Frontier Army," p. 477). Plympton
referred to the Second Fort as being of "peculiar construction,"
mentioning the placing of barracks and storerooms in the redans, which
Plympton referred to as demi-lunes (Arrott, cards 80, 81). In spite of
the problems with the fort, in August, 1862, preparations were being
made to place 14 pieces of artillery in the earthwork (Part I, p. 43).
By December, 1862, ten 12-pound cannon had been placed in the fort, and
"several" guns of larger calibre were being mounted (Mesilla Times,
Dec. 12, 1862).
An inspection of the fort during the summer of 1862
noted that the fortification was not completed by that time. The parapet
that formed the breastwork was washing away and filling up the ditch
around the earthwork. Also, the lack of ventilation and interior
moisture were causing serious problems. However, a major new
construction effort was begun in November, 1862. For example, additional
abatis were put in place on the fortification by December, 1862,
and bombproof magazines and barracks were constructed in late 1862 and
early 1863 (see HS-209, 210, 211, below).
Redan or Demilune. Officers' Quarters. Designed about
the first week of September, 1861, and completed by October 20, 1861. Of
the eight redans intended to house officer's quarters, only HS-201 and
202 appear to have been finished, based on the appearance on the ground
and Robb's description on June 30, 1862. Robb stated that both of the
completed and occupied quarters had the same measurements. They were
made up of a series of eight rooms each 16 feet across but of varying
lengths. The eight rooms formed two wings meeting at an angle, says
Robb; one side of the angle was made up of three rooms, two of them
18 feet long and the third 12 feet long. The other wing is formed by
five rooms, 14 feet, 14 feet, 12 feet, 8 feet, and 16 feet. Presumably
the 16 x 16 foot room formed the apex of the angle; if so, the two rows
of rooms were 64 feet long from apex to end. These quarters had board
The remains of HS-201 on the ground consist of a
number of fragments of rubble stone wall with occasional sections of
brick. Not enough of the structure is visible above ground to work out
the actual plan or to see any correspondence between Robb's description
and the physical remains. The appearance of the structural traces,
however, suggest that a large proportion of the building remains
relatively undisturbed in the ground; archeological investigation would
probably quickly reveal the details of the plan and individual room
Either these quarters or those of HS-202 were used as
the Commanding Officer's quarters from November 25, 1864, when HS-224
burned, through October, 1866, when Commanding Officer's Quarters HS-5
were completed. Brigadier General Kit Carson was Commanding Officer
during most of this period, December 24, 1865 to April 27, 1866 (Oliva,
"Frontier Army," p. 565). It is likely that HS-201 was the Commanding
Officer's Quarters; its remains are more substantial, suggesting that it
may have been maintained better and longer.
Redan or Demilune. Officers' Quarters (see
Redan or Demilune. Officers' Quarters, incomplete.
This redan is shown on the 1866 and 1868 maps, and is visible on the
ground, but no traces of structural remains can be found. It may not
have gotten beyond the excavation of foundation trenches.
Redan or Demilune. Company Quarters and storeroom.
Designed about the first week of September, 1861. Construction of the
buildings themselves largely finished by October 20. By December 15,
1861, the structures were finished and the ditches on their exteriors
were being excavated. The dirt was thrown up against the outside and top
of the building (Oliva, "Frontier Army," p. 475). Lieutenant Alexander
Robb described these quarters as well as the Officer's Quarters on June
30, 1862. He said that the redans housing the Company Quarters were each
composed of two wings; each wing was 200 feet long and 26 feet wide.
Each was divided into a storehouse 100 feet long, and quarters for a
single company made up of six rooms. Allowing for the thickness of the
partition walls, each Quarters room would therefore be 15-1/2 feet by 26
feet. They had packed-earth floors, rather than the board floors of the
Inspecting the earthworks quickly revealed the
general plan of these buildings on the ground. The Company Quarters were
located on the ends of the redans closest to the fieldwork, and had a
fireplace on every other wall; that is, each hearth served the two rooms
on either side of it. These fireplaces fell at intervals of 31 feet. The
chimneys of these fireplaces can be seen in the photographs of the
redans taken in 1865, with small air circulation stacks next to them
along the tops of the earth-covered buildings, one to each room. The
ditches on the outside of each building are largely silted up, but seem
to have been about 17 feet wide. The curved portion of the apex of each
redan was apparently solid earth. As with the Officer's Quarters,
considerably more detail about the construction of these buildings, as
well as the use of the various spaces, could be recovered by a careful
As new company quarters were completed in Third Fort,
men were moved out of the Second Fort barracks. Marian Russell lived in
one of the Company Quarters for a time in 1864 (Oliva, "Frontier Army,"
p. 757). By November, 1866, it was reported that no enlisted men
remained in the barracks at the earthworks (Oliva, "Frontier Army," p.
575). After abandonment, the buildings were used as laundresses quarters
from about November, 1866 to late 1867 (Oliva, "Frontier Army," p. 594;
Part I, p. 57), when the laundresses were moved into their new quarters
along the west side of the Post Corral.
Redan or Demilune. Company Quarters and storeroom.
Two of the barracks were converted to temporary stables beginning on
November 21, 1866; the Lambert and Inman map of January, 1867, shows
that one of these stables was in the eastern half of this redan. The
other was probably in the west half. The use of these barracks as
stables continued until completion of the Post Corral stables in late
Redan or Demilune. Company Quarters and
Redan or Demilune. Company Quarters and
Headquarters Offices? Probably designed and built as
part of the major reconstruction of November, 1862. This building has
very sharp edges and flat sides, and was apparently built with an
exterior casing of wood or stone. The featureless appearance suggests
stone as the more likely material. A thick layer of earth forms a cap on
the building. A single large ventilator is visible at about the center
of the cap in the ca. September, 1865, photographs. The flagstaff,
HS-225, for the Second Fort stood just north of this structure, probably
in front of the main entrance.
Company Quarters. Two of these structures are
mentioned in an article in the Denver Rocky Mountain News of February 24,
1862, and described by Lt. Robb on June 30, 1862; he says that they were constructed
inside the works but were only temporary, and would have to be rebuilt to be
permanent. Both of these were rebuilt as bombproof barracks during the
reconstruction of November-December, 1862; orders requiring this were
sent to Fort Union on December 20, 1862 (Part I, p. 54), indicating that
the work probably occurred in late 1862; however, a week earlier, on
December 12, 1862, the Mesilla Times described the Magazine
(HS-211), quarters (HS-209, 210, and 212) and "all the garrison
buildings" to be bombproofs already.
The ca. September, 1865, photographs shows some
details of this structure. Five ventilators or chimneys can be seen, one
at each corner of the roof, and one in the center. The main entrance to
the structure was a doorway at the south end near the southeast corner;
this is rather poorly placed, since it faces the opening of the main
gate of Second Fort, making it possible for a shot to pass over the
traverse covering the entrance and penetrate this doorway. The north end
of the building seems to have been built against the Headquarters
After the abandonment of Second Fort, HS-209 was dug
out and most of its useable material salvaged, leaving a large oval
Company Quarters. These Quarters were probably also
built as a bombproof building in November-December, 1862. The ca.
September, 1865, photographs shows some details of the building. It had
two doors, one on the south face at the west end, the other on the east
end near the northeastern corner. Six small loopholes or tiny windows
are spaced evenly along the south side. Five ventilators can be seen on
the roof, two at the west end, two at the east, and one in the center;
all seem to be offset somewhat towards the south edge of the roof. No
chimneys can be made out in the photograph, but various odd marks on the
roof could be partly demolished chimneys.
This building appears not to have been dug out for
salvage; it is possible that the structure collapsed in place. If so, a
great deal of structural information waits to be found by archeological
Magazine. Plans for a bombproof magazine within
Second Fort were discussed on November 26, 1862. Captain Shoemaker
suggested that the building should be about 60 feet long and 25 feet
wide, excavated 8 feet into the ground and walled with upright timbers
faced with rough boards. The wall timbers were to be 14 feet high, with
the roof beams of horizontal timbers resting on the side walls and
supported in the center. The beams would slope downwards from the
centerline towards the walls, and would be covered with boards and at
least 3 feet of earth. A door was to be placed at each end, and a board
floor built of planks on joists. This magazine was begun in late
November, 1862, and completed in December (Part I, pp. 52-53, 54; Oliva,
"Frontier Army," p. 548-49). It was still in use for vegetable storage
for the Post Commissary in October, 1867 (Oliva, "Frontier Army," p.
Officers' Quarters. According to 1st Lt. Alex W.
Robb, June 30, 1862, one officer's quarters with four rooms stood in
Second Fort by the time of his inspection, but was apparently not a
bombproof structure. However, it was rebuilt as one in late 1862,
probably at the same time as the two barracks and the magazine (HS-209,
210, and 211) were built in November and December, 1862. The ca.
September, 1865, photographs shows the building as a bombproof with two
chimneys, one on the north and one on the south center of the roof, and
a ventilator on the east side.
Well. A well was under construction within the
earthworks by early January, 1862, apparently begun after the collapse
of the water supply tunnel (HS-222) in late 1861. Eventually, three
wells appear to have been dug. HS-213 and HS-214 were inside the
Well? Unlike the two wells above, this circular
structure is located in one of the redans. It is possible that this is
not a well; however, no suggestion of any other structure is
Traverse? This structure, of packed earth, was
designed to prevent incoming fire from passing through the gap in the
parapet formed by the main gate.
Workshops, Offices, and Temporary Storehouses.
Probably built in August and September, 1861 (Part I, p. 44). This is
actually a series of several buildings in a row, as can be seen in the
ca. September, 1865, photographs. At least seven or eight chimneys are
visible in these photographs, several of them producing smoke. The first
building on the northwest end appears to be made of canvas on a wooden
frame. At its southeast end is a large rectangular object standing well
above its gabled roof; this looks like a large chimney. Next is a low
structure, apparently of wood, with a shed roof of shallow slope. A
small chimney appears at its southeast end. At its north end, obscuring
the point where it contacts the canvas building, is a small room
extending north at right angles to the main line of the series of
buildings. This room is made of horizontal logs, and has a flat roof.
Southeast of the shed-roofed building is a long building with four or
five chimneys and a gable roof. At least one other chimney is producing
smoke past the visible end of the long building, but no further details
can be seen.
Workshops and Offices. No clear traces of this
building can be seen on the ground. It is known to exist only from its
presence on the 1866 and 1868 maps, and because
two photographs of Second Fort were taken from the
top of some structure in this location in 1865.
Embrasured Gun Batteries. These guns fired through
embrasures, or slots in the parapet, located on the faces, flanks and
curtains of the fort. There are 24 of the platforms for these batteries;
at least three can be seen in the ca. September, 1865, photographs; the
straight line of the wooden platform is easily recognized in the
pictures. At least seven embrasures can also be seen cutting the
parapets of the fort.
Gun Batteries en barbette. These batteries are
somewhat conjectural, pending archeology. Four positions for guns firing
over the parapet, rather than through an embrasure, at the salients (the
points of the bastions) of the fort. Unfortunately, none of the salients
are visible in the 1866 photographs. The western bastion contained a
6-pound gun in June, 1862 (Arrott, card 81); whether this was at the
salient is unknown. For purposes of comparison, see the plan of the
Confederate star fort built at Arkansas Post, built in 1862; Roger E.
Coleman, The Arkansas Post Story:
Arkansas Post National Memorial, Southwest
Cultural Resources Center, Professional Papers no. 12 (Santa Fe:
National Park Service, 1987), p. 105, fig. 33. This fort had several
guns set up en barbette, one of them at the southeast salient;
the other eleven gun positions were apparently embrasured, including
those in the other three salients. See also the plan of fortifications
at the mouth of the Rio Grande, "map of the North End of Brazos Island,"
prepared in 1865 by Captain D. C. Han, Army Engineers, in the collection
of Palo Alto Battlefield National Historic Site, Texas. This map shows
the specifics of an octagonal fortification including a plan of its gun
platforms and a cross-section of the platforms and parapets, with
construction details. The specifics of the barbette and
embrasured guns shown on this plan match those reconstructed from the
surviving traces of the Fort Union fortification quite closely.
Tunnel. This was a tunnel for getting water from a
cistern near the bank of Coyote, (or Wolf) Creek, rather than an "escape
route," as most of the speculation about it seems to assume. A brief
description of the tunnel appears in the Santa Fe Republican,
July 5, 1862, p. 1, "Fort Building in New Mexico." The article
indicates that the tunnel had been built in 1861 as a means of insuring
a water supply for the fort. Soon after being finished, part of the
tunnel collapsed; about the same time, in December, 1861 or early
January, 1862, wells dug in the fortifications reached water (Arrott
card 72, Oliva, "Frontier Army," pp. 394-95; see also HS-213, 214, 216),
giving a better source for the needs of the garrison and making the
tunnel unnecessary. The tunnel was lined with boards and was about 3 to
3-1/2 feet in width. It was about 4 feet high, roofed with planks, and
had earthen sides shored with boards every few feet (Part I, p. 58). It
appears to have begun in the outer slope of the south ditch, under the
entrance bridge (HS-223, below). It ran southwest from the Star Fort for
about 950 feet, apparently to a covered cistern about 100 feet from
the present creek bank. The last 250 feet before
reaching the cistern shows a wider and deeper depression, along which
can be found board fragments, suggesting that this part of the tunnel
may have been the area of collapse; or it may have been dug out. The
rest of the length probably preserves much of the tunnel structure
Bridge. The 1866 map shows some sort of narrow
crossing of the south ditch of Second Fort, giving access to the main
entrance through the parapet. On the ground, this appears as a short
stub of an earthen ramp extending about 30 feet from the south side of
the ditch towards the main entrance. The remaining 35 feet had no such
ramp; the floor of the ditch continued across this area unbroken.
However, several mounds of large cobbles and small boulders seem to have
a certain symmetry to their location. When plotted, the evidence
indicates that the inner 35 feet of the entrance ramp was of wood,
supported on massive posts partially protected by mounds of stone.
Provision was probably made to raise or destroy some part of, or all of
this bridge, in time of attack.
Commanding Officers' Quarters, Second Fort. In
February, 1863, an order came through to salvage building materials from
the Sumner House at First Fort and constructed a new temporary officer's
quarters near the fieldwork of Second Fort. The choice of site was left
up to the discretion of the commanding officer. The building was
supposed to be a temporary log building plastered on the interior "with
blinds for the windows and a gallery running along its front, say ten
feet broad." The building was supposed to have a roof of lumber and
chimneys of stone. These quarters were occupied by April, 1863 (Part I,
pp. 38-39, 54-55). HS-224 appears to be the Commanding Officer's
Quarters that burned on November 25, 1864, completely destroying the
building and apparently forcing the commander to move to one of the
officer's quarters in the redans, probably HS-201 (Oliva, "Frontier
Army," p. 540).
The arroyo has cut into the southeast corner of the
structural remains, but still a good deal of scattered fieldstone and
trash are easily seen. At least two areas that appear to be the remains
of chimney bases are identifiable.
Flagstaff, Second Fort. Approximate location. The
photographs of ca. September, 1865, show the flagstaff standing just
north of the Headquarters building, HS-208, on the centerline of the
fort and apparently centered between the Headquarters building and the
Magazine, HS-211, just to the north; it was probably in front of the
main entrance to the Headquarters building. Probably erected in June,
1862, and a request for a garrison flag submitted to Headquarters, Santa
Fe, on June 27. Still standing with a flag flying in ca. September,
1865. Archeological excavation would probably confirm the exact location
of the flagstaff.
Last Updated: 13-Feb-2006