August was a busy month on Morris Island, 150 years ago. And the busiest days occurred from August 17 through 23 with the simultaneous bombardment of Fort Sumter, advance of the siege lines against Battery Wagner, and the little matter of a Parrott Gun firing on Charleston. Add in Confederate attempt to sink the USS New Ironsides and the week’s worth of activity becomes one of the most interesting of the war. Not to be outdone by the actions of man, a gale blew in from the Atlantic Ocean on August 18 and continued through the 21st. What we would refer to as a “storm surge” in combination with a spring tide filled the trenches of the parallels and boyaux with water. The storm also took out the surf battery’s parapet, and forced the temporary removal of the howitzers. The aim of the heavy Parrott guns was not significantly affected by the storm’s winds, so the big guns continued their work. However the same could not be said for the work advancing the siege lines towards Battery Wagner.
After the construction of the third parallel earlier in August, Brigadier-General Quincy Gillmore suspended the advance of more parallels pending the bombardment of Fort Sumter. On the night of August 18, Gillmore ordered the engineers to resume the advance, despite the weather. Major Thomas Brooks recorded minimal work was completed that night:
… the trench of this parallel was cleared out and widened, the parapet strengthened, and the debouch made. A Requa battery was placed in position on the extreme left of the third parallel, to enfilade the front of the parapet of the proposed sap. Sap-rollers and sapping tools were carried forward. The extreme high tide, requiring the men to work in mud and water, greatly interfered with all these operations.
The immediate objective of the next parallel was to reach past a set of fingers extending from the marshes, which neared the beach at several points. This was the narrowest section of Morris Island, and which had proved so difficult to traverse in the July assaults on Battery Wagner. Accordingly the engineers approached with careful deliberation and caution. Adding to the difficulty were the presence of Confederate sharpshooters on a sand ridge in front of Battery Wagner. Referencing the map below, provided by Colonel Edward Serrell in his report, the sand ridge is to the right (however, disregard the location of the fourth parallel for the moment).
The plan was to run the sap out from the third parallel past those marsh fingers. Then construct a parallel running from the beach across to the marshes. Such would put the next parallel within 200 yards of Battery Wagner. The work resumed in the early morning hours of August 19:
This morning at 2 o’clock, the water having so subsided as to render it possible, the full sap was started from the point above indicated, by Captain [Joseph] Walker, with a sapping brigade, consisting of 10 men from his own company (I, New York Volunteer Engineers). He had executed 60 feet at 8 a.m., and was then relieved by Captain [John L.] Suess, with a sapping brigade from his company (B), same regiment, who completed 70 feet of approach during the day. The enemy’s sharpshooters opened on the head of the sap as soon as they observed its progress in the morning, and fired at it all day. One casualty occurred among the sappers, a slight wound from the explosion of a shell. Captain Walker again took the advance this night, and, by means of the flying sap, executed about 160 yards of approach, leaving the sap-roller at daybreak in position several yards in advance of our picket line.
The advance here being measured in yards, with the Federals then about 200 yards closer to Battery Wagner, but without a parallel. As indicated by Brooks, the sapping details worked in shifts, and cycled through rest periods similar to those of the men in the breaching batteries. With that work ever so close to Confederate lines, Brooks made arrangements for an advanced guard, consisting of a full regiment of infantry, positioned in the forward trenches of the third parallel (and recall the “keeps” of that trench line).
On the morning of August 20, a detail under Lieutenant Charles Wilcken took over the work on the sap. The work proceeded slowly during the day. Three of the detail were injured. By mid day, Captain Suess’ detachment took up the work. Finally around six that evening, Lieutenant Charles Parsons brought a fresh detail into the trenches. Six hour shifts during daylight hours, with longer runs at night.
Captain Walker’s detail returned to the sap at 3:30 am on August 21,
… at which time the enemy were directing a heavy fire of grape and canister upon it, which fire ceased before daylight. This permitted him to place a line of gabions on the reverse side of the trench, to shield the sappers from the enemy’s sharpshooters, who, it was feared, would occupy the cover furnished by the old ruins to the front and head of the sap.
At that point, the engineers could not move farther forward. Artillery fire from Battery Wagner and sharpshooters on the ridge kept the sappers pinned down. When Wilcken’s crew took over duties, he was forced to retire. A flag of truce went out at 11:30, but by noon hostilities resumed.
In response to this resistance, the Navy brought up the USS New Ironsides and several gunboats to fire on Battery Wagner. Likewise the 30-pdr Parrotts and field guns in the Federal batteries fired in support of the sappers. General Alfred Terry ordered up the 100th New York Infantry, under Colonel George B. Dandy, from the keeps of the third parallel to conduct an evening assault on the Confederates on the ridge. Despite several attempts and the loss of six men, the New Yorkers could not gain the ridge.
Brooks considered the situation that night and determined to at least secure what was gained:
I examined the ground, and concluded to establish a fourth parallel, in order to secure possession of the ruins on the elevated ground to the left, from which the enemy’s sharpshooters had long given us so much annoyance, and to increase our front preparatory to another attempt to take the ridge. This parallel, comprising a linear development of 300 yards, was opened from the beach to the marsh, close along the heels of our outposts (its right being 350 yards from Wagner), by Captain Suess. He reports most part of the work was done by means of the flying sap, the engineers placing the gabions and the negro troops (Third Regiment United States Colored) digging the trench. The part on the left, near the ruins, being constantly swept by the enemy’s musketry fire, was performed by the full sap; not, however, using the sap-roller, as a flank fire only had to be provided against. The details for this advanced work this night were 100 infantry and 15 engineers.
The resulting trench lines appear on Brooks map of the approaches to Battery Wagner (here with the third and fifth parallels for context):
I’ll save the discussion of the Requa and coehorns for later. But notice the fourth parallel fit between two of the marsh fingers. At first glance, this might seem a bad position. But the extent of 300 yards of trenches allowed more room to maneuver for the Federals.
Brooks offered two profiles of the trenches on the fourth parallel. The line m-m’ was across the approach boyaux just behind the parallel. Here the engineers used a barrel to help form a step up to the banquette.
Profile n-n’ was along the actual parallel trench. Here the engineers used gabions to raise the height of the works and allow the infantry to better defend the line.
Notice that in both profiles the trench’s ditch was wide enough to accommodate more troops, equipment, and weapons.
I’ve run a bit long in the description of the fourth parallel. But much of that was a “setup” of sorts. The take away here was how the action at the point of advance evolved into something which had similarities to … say… actions in the Central Pacific during World War II. An assault force worked foot by foot against an entrenched enemy, supported by heavy artillery and naval gunfire. Covering fire from the Billinghurst-Requa “machine-guns.” No fancy maneuvers to consider. Close quarters night actions. Spade, musket, and bayonet. And the fighting along the fourth parallel was just starting as August 22 dawned. The Confederates could not let this advance could not go uncontested.
(Citations from OR, Series I, Volume 28, Part I, Serial 46, pages 288-290.)