V
icksburg remains the classic
example of a Civil War siege. On
May 25, 1863, General Ulysses S.
Grant, looking up the bluff at fortified
Vicksburg, released his Special Order
140: “Corps Commanders will
immediately commence the work
of reducing the enemy by regular
approaches.” Every officer knew what
“regular approaches” entailed: It
meant digging their way up the
hill. Its aim was a kind of slow,
subterranean strangulation, the
attacker taking every advantage of
terrain to move his forces, with small
loss of life, close enough to smash a
defender’s fortifications with artillery.
Improvised attack
When Grant attacked Vicksburg, his
army had just fought its way through
the Mississippi swamps. He had no siege
equipment, no engineering troops, and
no siege train. As his soldiers dug their
way up the bluff, they improvised
building materials and made serviceable
mortars from wooden cylinders wrapped
in iron bands. A 12-mile (19-km) coil of
Wooden quadrant
This simple quadrant was used by gunners
to check the elevation of a cannon
in order to give the shell
the correct angle of
trajectory to hit
its target.
Siege Artillery and Siege Warfare
Throughout history, armies have laid siege to cities and citadels. The Civil War sieges combined established
techniques of siegecraft, including the choking off of supply routes and the undermining of fortifications,
with the deployment of more modern and powerful heavy artillery.
GRANT, SHERMAN, AND TOTAL WAR 1864
siege works tightened
around Vicksburg. A second
line of works was built around the
first but facing outward to repel any
Confederate attempt to lift the siege.
At Vicksburg, Grant also used mining
techniques. He laid several kinds of
mine, including one resembling a
smaller version of the densely packed
mine that triggered the Battle of the
Crater at Petersburg. Finally, Grant
won the artillery duel with only his
field artillery and some heavy ordnance
loaned to him by Union gunboats.
Heavy artillery old and new
Siege artillery was often dwarfed by
coastal artillery: large-caliber Columbiads
and similar monsters fired from fixed
platforms. By the
time of the Civil
War, however,
these great
smoothbores and
their enclosing forts were becoming
obsolete, as new artillery with rifled—
or grooved—barrels came into use.
These weapons were faster to fire,
more accurate, and had a greater range.
The thick masonry walls of Fort Pulaski
outside Savannah were reduced to
rubble in two days in April 1862 by the
new rifled ordnance of the Union fleet.
Earth forts fared better, however, as
they absorbed the blow and shock of an
exploding shell. Battery Wagner outside
Charleston, made of packed dirt, sand,
and palmetto logs, withstood weeks of
bombardment before the Confederates
abandoned it and its 14 coast guns. These
included a 10-in (250-mm) Columbiad
that fired a 128-lb (58-kg) shell.
BEFORE
After the War of 1812, the United States
began constructing a series of masonry
forts to protect its harbors and coastal
cities from invasion.
AMERICAN COASTAL ARTILLERY
Because they constituted the nation’s first line
of defense, the heavy guns in the forts had
received most of government spending on
ordnance (weapons and ammunition), much
more than had the field artillery ❮❮ 128–29.
Most of the guns were 8- and 10-in (200- and
250-mm) smoothbore Columbiads, muzzle-
loading cannons invented in 1811.
CONFEDERATE COASTAL ARTILLERY
By 1861, more than 60 forts and batteries
ringed the U.S. coast. Some were so lightly
manned, however, that the Confederate
states were able to seize them and their
guns intact, thus gaining a wide range of
heavy artillery at the start of the war.
Augmented by imports from Britain and
guns made by the few cannon foundries in
the South, this artillery would defend not
only the forts of the Confederacy, but also
such besieged cities as Vicksburg
❮❮ 190–95 and Petersburg ❮❮ 274–75.
Many of these huge guns eventually
blew up, because of flaws in casting
technology. On average the South’s
ordnance and munitions proved the
more unstable, but Union guns often
exploded, too. During the 1863–64
siege of Charleston, the “Swamp
Angel,” a 24,000-lb (10,890 kg), 8-in
(200-mm) Parrott gun, had the dubious
distinction of shooting the first
incendiary shells into the city; but it
blew up after only 36 rounds.
Civil War sieges
In the 1862 Peninsula Campaign,
General George B. McClellan dragged a
massive siege train through the Virginia
swamps. No fewer than 101 guns—
with 20-, 30-, and even 100-pounder
(9-, 14-, and 45-kg)
Parrott guns and
huge mortars—
were erected on
platforms before
Yorktown, itself “protected” by a few
fake cannons, or “Quaker guns,” named
for the pacifist Quakers.
In the Civil War, the term “siege” was
often applied to any grinding struggle
involving fortified positions—Atlanta
and Petersburg among them. These
battles borrowed many elements of
traditional sieges, including mining,
countermining, labyrinths of enclosed
entrenchments, and the often
commanding use of heavy artillery.
Sherman had been at Vicksburg, but
he once declared, “I’m too impatient for
a siege.” In 1864, when he attacked
Atlanta, the city was ringed with
fortifications, but most of the fighting
took the form of battles of maneuver
“The sky was lit up by the broad
flame of mortars and by the
twinkling and shooting stars ...”
A. S. TWITCHELL, 7 MAINE LIGHT BATTERY, AT PETERSBURG, MARCH 29, 1865
Deceptive defenses
Short of real guns, the Confederacy turned to “Quaker
guns,” logs set in embrasures and painted to look like
cannon barrels, to intimidate the enemy. Here a
“gunner” pretends to fire the weapon.
Rule
Quadrant,
marked in
degrees
Plumb bob
Estimated number
of mortar shells fired
during the ten-month siege of Petersburg.
80,000