At several places east of the city the opposing lines were extremely
close together. One of these locations was in front of Pegram’s
(sometimes called Elliott’s) Salient, a Confederate strong point near
old Blandford Church. Here the Confederate position on Cemetery Hill and
the Union picket line were less than 400 feet apart. Because of the
proximity of the Union line, Pegram’s Salient was well fortified. Behind
earthen embankments was a battery of four guns, and two veteran South
Carolina infantry regiments were stationed on either side. Behind these
were other defensive works; before them the ground sloped gently
downward toward the Union advance line.
This forward Union line was built on the crest of a ravine which had
been crossed on June 18. Through this ravine, and between the sentry
line and the main line, lay the roadbed of the Norfolk and Petersburg
Railroad. The front in this sector was manned by Maj. Gen. Ambrose E.
Burnside’s IX Corps. Among the many units which composed this corps was
the 48th Regiment, Pennsylvania Veteran Volunteer Infantry. A large
proportion of this regiment was made up of onetime coal miners, and it
apparently occurred to one or more of them that Pegram’s Salient would
provide an excellent place to use their civilian knowhow. Lt. Col. Henry
Pleasants, the commanding officer of the 48th and a mining engineer by
profession, overheard one of the enlisted men mutter, “We could blow
that damned fort out of existence if we could run a mine shaft under
it.” From this and similar remarks came the germ of the idea for a Union
mine.
The 48th Regiment proposed to dig a long gallery from the bottom of the
ravine behind their picket line to a point beneath the Confederate
battery at Pegram’s Salient, blow up the position by powder placed in
the end of the tunnel, and then send a strong body of troops through the
gap created in the enemy’s line by the explosion. They saw as the reward
for their effort the capitulation of Petersburg and, perhaps, the end of
the war.
After obtaining the permission of Burnside and Grant, Pleasants and his
men commenced digging their mine shaft on June 25. The lack of proper
equipment made it necessary to improvise tools and apparatus with which
to excavate. Mining picks were created by straightening army picks.
Cracker boxes were converted into hand-barrows in which the dirt was
removed from the end of the tunnel. A sawmill changed a bridge into
timber necessary for shoring up the mine. Pleasants estimated the
tunnel’s direction and depth by means of a theodolite sent him from
Washington. The instrument, although outmoded, served its purpose well:
the mine shaft hit exactly beneath the salient at which it was aimed.
[Illustration: _Lt. Col. Henry Pleasants, onetime mining engineer
and the commanding officer of the 48th Pennsylvania Regiment which
dug the tunnel under the Confederate line._]
[Illustration: _Cross-section view of the Federal tunnel under the
Confederate line. Colonel Pleasants later recalled that “General
Burnside told me that General Meade and Major Duane, chief engineer
of the Army of the Potomac, said the thing could not be done—that it
was all clap-trap and nonsense; that such a length of mine had never
been excavated in military operations, and could not be; that I
would either get the men smothered, for want of air, or crushed by
the falling of the earth; or the enemy would find it out and it
would amount to nothing.”_]
Air tube
Air-tight door
Fireplace
Chimney
FEDERAL LINE Established June 18, 1864
Tunnel sloped up to avoid heavy clay
Air tube
JUNE 25, 1864, Tunnel started
510-8/10 feet
JULY 27, 1864, 8,000 lbs. of powder placed here
CONFEDERATE LINE
JULY 30, 1864, Pegram’s Battery destroyed by explosion
One of the most remarkable features of the gallery was the method
devised to supply the diggers at the end with fresh air. The longer the
tunnel grew, the more serious the problem of ventilation became. It had
been considered impossible to dig a tunnel for any considerable distance
without spacing shafts at regular intervals in order to replace the
polluted air with a fresh supply. This problem had been solved by the
application of the simple physical principle that warm air rises. Behind
the Union picket line and to the right of the mine gallery, although
connected with it, the miners dug a ventilating chimney. Between the
chimney and the mine entrance they erected an airtight canvas door.
Through that door and along the floor of the gallery they laid a square
wooden pipe. A fire was then built at the bottom of the ventilating
shaft. As the fire warmed the air it went up the chimney. The draft thus
created drew the bad air from the end of the tunnel where the men were
digging. As this went out, fresh air was drawn in through the wooden
pipe to replace it.
Work on the tunnel continued steadily from June 25, and by July 17 the
diggers were nearly 511 feet from the entrance and directly beneath the
battery in Pegram’s Salient. The Confederates had learned of the mine by
this time and had dug several countermines behind their own lines in an
effort to locate the Union gallery. Two were very close, being dug on
either side of where the Pennsylvanians were at work. Although digging
in the countermines continued throughout July, Confederate fears seemed
to lessen during the same period. There were many reasons for this, one
being the failure of their tunnels to strike any Union construction.
Another major reason, undoubtedly, was a belief held by many that it was
impossible to ventilate a shaft of any length over 400 feet without
constructing air shafts along it, and so far no air shafts could be seen
between the Union and Confederate lines.
The next step in the Union plan was to burrow out into lateral galleries
at the end of the long shaft. Accordingly, on July 18, work was begun on
these branches which extended to the right and left, paralleling the
Confederate fortifications above. When completed, these added another 75
feet to the total length of the tunnel which now reached 586 feet into
the earth. It was about 20 feet from the floor of the tunnel to the
enemy works above. The average internal dimensions of the shaft were 5
feet high, with a base 4½ feet wide tapering to 2 feet at the top.
Digging was finally completed on July 23. Four days later the task of
charging the mine with black powder was accomplished. Three hundred and
twenty kegs of powder weighing about 25 pounds each were arranged in the
two lateral galleries in eight magazines. The total charge was 8,000
pounds. The powder was sandbagged to direct the force of the explosion
upward and the fuses were spliced together to form a 98-foot line.
Meanwhile, preparations for the large-scale attack which was to follow
the explosion of the mine had been carried out. Burnside wanted his IX
Corps to lead the attack, spearheaded by a fresh, 4,300-man Negro
division, and pressed his wishes on Meade. Both Meade and Grant approved
the request, but refused to allow the black troops to lead the assault
for fear that, if the attack failed, the Union commanders could be
accused of wanting to get rid of the only Negro troops then with the
Army of the Potomac. Burnside did not learn of this decision until the
day before the assault, July 29, and he was forced to change his plans
at the last moment. Three white divisions would make the initial charge,
with the black division in reserve. Burnside had the commanding generals
of these three divisions draw straws to see which would lead. Brig. Gen.
James F. Ledlie of the 1st Division won the draw.
Despite these 11th-hour changes, a plan of battle had been evolved.
During the night of July 29-30, the bulk of the IX Corps was assembled
in the ravine behind the mine entrance and in the two approach trenches
leading to the picket line. Troops from other Union corps were
marshalled as reinforcements. Artillerymen, manning 110 guns and 54
mortars, were alerted to begin shelling the Confederate line. To assist
the attack, Grant sent a cavalry and infantry force north of the James
to threaten the Richmond defenses and destroy whatever they could of the
Virginia Central Railroad. The object was to draw as many of Lee’s
soldiers away from Petersburg as possible. And it worked. When the
assault came, only 18,000 Confederates were left to guard the city.
At 3:15 a.m., July 30, Pleasants lit the powder fuse and mounted the
parapet to see the results of his regiment’s work. The explosion was
expected at 3:30 a.m. Time passed slowly and the men, huddled behind the
lines, grew more apprehensive. By 4:15 there could be no doubt that
something had gone wrong. Two volunteers from the 48th Regiment (Lt.
Jacob Douty and Sgt. Harry Reese) crawled into the tunnel and found that
the fuse had burned out at a splice. They relighted it and scrambled to
safety. Finally, at 4:40 a.m., the earth trembled, and with one great
roar, men, equipment, and debris were hurled high into the air. At least
278 Confederate troops were killed or wounded in the tremendous blast,
and two of the four guns in the battery were destroyed beyond repair.
The crater torn by the powder was at least 170 feet long, 60 to 80 feet
wide, and 30 feet deep.
The awesome spectacle of the mine explosion caused a delay in the Union
charge following the explosion. Removal of obstructions between the
lines caused further delay. Soon, however, an advance was made to the
crater, where many of the attacking force paused to seek shelter on its
steep slopes or to look at the havoc caused by the mine. The
hard-pressed Confederates rallied quickly and soon were pouring shells
and minié balls into their opponents. Union reinforcements poured into
the breach; but, instead of going forward, they either joined their
comrades in the crater or branched out to the immediate right and left
along the lines. By 8:30 that morning a large part of the IX Corps had
been poured into the captured enemy salient. More than 15,000 troops now
milled in and about the crater.
By prompt action and determined effort the Confederates had prevented a
breakthrough. The attention of three batteries was soon directed on the
bluecoats at the crater. Artillery hammered with shot and shell the
huddled groups of increasingly demoralized men. In addition, mortars
brought to within 50 yards of the crater dropped shells on the soldiers
with deadly effect.
Successful as these devices were in halting the Union advance, Lee was
aware that an infantry charge would be necessary to dislodge the enemy.
By 6 a.m. an order had gone out to Brig. Gen. William Mahone to move two
brigades of his division from the lines south of Petersburg to the
defense of the threatened position; Mahone had anticipated the order and
already had his troops in motion. Then Lee joined Beauregard in
observing the battle from the Gee house, 500 yards to the rear of the
scene of action.
[Illustration: _Colonel Pleasants’ sketch of the Crater._]
_Outline of Crater._
_Course of Confederate Works._
_S & E_
_Magazines._
In spite of the Confederate resistance, part of the Northern black
division and other regiments had, by 8 a.m., advanced a short distance
beyond their companions at the crater. Shortly thereafter, Mahone’s lead
Confederate brigade arrived on the scene. The men filed into a ravine
about 200 yards northwest of the crater and between it and Petersburg.
No sooner had they entered this protected position than, perceiving the
danger to their lines, they charged across the open field into the mass
of Federal soldiers. Although outnumbered, they forced the Northerners
to flee back to the comparative shelter of the crater. Then they swept
on to regain a portion of the line north of the Union-held position.
[Illustration: _To many soldiers, the explosion of the mine and the
bitter Battle of the Crater that followed were the most memorable
events of the siege. Artist A. R. Waud sketched the explosion from
the Union lines._]
By 10:30 another of Mahone’s brigades had reached the point of danger,
and it charged the Union troops holding the crater, only to be repulsed.
Meanwhile, the lot of the Northern soldiers was rapidly becoming
unbearable. Confederate artillery continued to beat upon them. The
closely packed troops (dead, dying, and living indiscriminately mixed)
lacked shade from the blazing sun, food, water and, above all, competent
leadership. Meade had ordered their withdrawal more than an hour before
the second Confederate charge, but Burnside delayed the transmission of
the order till after midday. Many men had chosen to run the gantlet of
fire back to their own lines, but others remained clinging to the
protective sides of the crater.
The last scene in the battle occurred shortly after 1 p.m. Mahone had
called up a third brigade, and an attack spearheaded by the fresh unit
succeeded in gaining the slopes of the crater. Some of the Union men,
overcome with exhaustion and realizing the helplessness of their
situation, surrendered; but others continued to fight. At one point
where resistance centered, the Confederates put their hats on ramrods
and lifted them over the rim of the crater. The caps were promptly torn
to shreds by a volley of minié balls. Before their foe could reload,
Mahone’s forces jumped into the crater where a desperate struggle with
bayonets, rifle butts, and fists ensued.
Soon it was all over. The Union army had lost more than 4,000 men
killed, wounded, or captured, as against about 1,500 for the
Confederates. Again, as on June 15-18, a frontal assault had failed to
take the Confederate stronghold, even though Union numerical strength
greatly exceeded that of the Confederates. At the battle’s close Grant
had more than 83,000 men south of the Appomattox River; Lee had about
22,000.
[Illustration: _What 8,000 pounds of powder could do—the crater as
it appeared in 1865. The Union soldier seated at the end of the
tunnel gives an idea of the crater’s size._]