The charge of the Iron Fleet

In late December 1862, the US Navy began considering plans to strike at Charleston, South Carolina. The genesis of the idea came from the commissioning of the 18-gun armoured cruiser New Ironsides, and the recent completion of a squadron of four monitor-style ironclads. In this force, naval planners saw an opportunity.

Fort Sumter, the primary obstacle to entering the harbour, was an old masonry work, and thus far in the conflict none of the old masonry forts had been able to withstand a barrage of heavy cannon. Fort Macon, Fort Pulaski, and even Fort Sumter itself at the start of the conflict had fallen to the power of modern artillery.

Thus, it was thought that if the monitors, with their powerful 15-inch and 11-inch Dahlgren guns, could get close enough to reduce the fort and push on into the harbour, it would create a panic among the defenders. An attack by 10,000 Union troops on nearby James Island would exploit this panic, and, hopefully, take the town by storm.

The plan placed a great deal of emphasis on the partially tested abilities of the new warships, and foolishly played down the role of the Army. But given the symbolic nature of Charleston and its role as one of the primary supply ports of the Confederacy, it was deemed worth the risk.

Fort Sumter

US Secretary of the Navy Gideon Welles wrote to Rear Admiral Samuel Du Pont at Port Royal, South Carolina, on 6 January 1863 assigning him the task. ‘The New Ironsides, Passaic, Montauk, Patapsco, and Weehawken, ironclads, have been ordered to, and are now on the way to join your command to enable you to enter the harbour of Charleston and demand the surrender of all its defenses.’ While some assistance might come from the Army, Welles pointed out that this was foremost a naval mission. ‘The capture of this most important port, however, rests solely upon the success of the naval force, and it is committed to your hands to execute.’

The target of Du Pont’s attack, Fort Sumter, was at the heart of a defensive complex that at the time made Charleston one of the most strongly fortified cities in the world. Built on a two-and-a-half-acre artificial island in a set of shallows on the southern side of the main channel, Fort Sumter was a pentagon-shaped structure with the salient angle aligned close to north.

The 200ft-long walls on either side of this northern point connected to a pair of curtain walls of similar length, facing east and west, which terminated at right angles with the 350ft-long south wall of the structure. Rising from the water’s edge, the inner and outer walls of Fort Sumter were 40ft tall and built of fired brick.

Backed by wooden arches and reinforced casemates to protect the garrison, the outside wall varied from five to ten feet in thickness. The height of the walls allowed for two tiers of enclosed firing ports, much like the gun decks on a large warship of the time. The open top level was protected by a brick parapet, along which a series of firing platforms were laid out for guns to fire en barbette.

Garrisoned by 550 men of the 1st South Carolina Artillery, boasting 79 guns, over half of which were 8-inch or greater, and backed by a battery of 10-inch coastal mortars in the parade ground, Fort Sumter would prove a difficult target for any fleet.

Other defence-works

However, it was not just Fort Sumter that an attacker would have to face when attempting to enter the harbour. Almost 1,800 yards across the main channel from the fort lay three fortified positions. The westernmost was Battery Bee, mounted by a dozen heavy guns. Just east of this was old Fort Moultrie, mounted by 38 guns along its earth and brick ramparts, and a few hundred yards further east was the five-gun Fort Beauregard.

Together with the guns of Fort Sumter and smaller batteries at Fort Wagner, Cummings Point, and even Fort Johnson, Charleston Harbor presented a formidable barrier to any intruder.

An additional defence, while seemingly innocuous, would have an important bearing on the upcoming engagement: a floating barricade that had been erected from Battery Bee towards Fort Sumter.

The initial attempt at construction with chained logs anchored at periodic points was destroyed by the tides, so a rope obstacle was chosen to replace it. Two rows of rope netting were strung across the broken wooden barrier, leaving a 300-yard section of the channel in front of Fort Sumter the only unobstructed path into Rebellion Road and the inner harbour – and even this section could be closed with a small boat.

Attached to these nets were 15ft rope tentacles designed to entangle propellers and paddlewheels. More importantly, a series of floating barrels secured the top part of the obstruction, giving the impression that barrel torpedoes (mines) had been connected to the barricade – though there had not actually been time to do this.

Concentrated firepower

For General Pierre Beauregard, who had taken command of Charleston in August 1862, the key to Confederate success was concentrated firepower. ‘The introduction of heavy rifled guns and iron-clad steamers in the attack of masonry forts,’ he wrote of his work, ‘has greatly changed the conditions of the problem applicable to Fort Sumter when it was built, and we must now use the few and imperfect means at our command to increase its defensive features as far as practicable.’

This meant earthworks and heavy cannon. The former Beauregard had seen to, but although he had close to a hundred of the latter, he warned that this might not be enough. Even so, he remained confident. ‘The enemy may destroy this city,’ he wrote to his friend, ‘but they shall not take it so long as I have any troops to defend it with.’

When sizeable detachments of Union troops began occupying locations on nearby Folly and Coles Islands in early April 1863, Beauregard suspected that an attack would soon develop. Reports had already reached him concerning a large number of troop transports at Port Royal and the departure of Du Pont’s ironclad squadron with a portion of these transports.

Whatever doubts that remained vanished on the afternoon of 5 April, when Du Pont’s ironclads, accompanied by a number of wooden gunboats, appeared off Charleston’s main bar.

While Du Pont had agreed to launch an ironclad attack on Fort Sumter, he had delayed the execution of the project for several months until four more ironclads had been completed. Three of these, the Catskill, Nantucket, and Nahant, were monitor-class vessels, while the fourth and last to arrive was the odd-looking Keokuk – an experimental ironclad with a rounded hull and a pair of fixed turrets, each of which contained an 11-inch Dahlgren cannon that could be fired from one of several ports. Like several of the monitors, the Keokuk had been rushed to Du Pont after a brief sea trial.

The attack begins

While the Admiral faced no issues in crossing the bar, weather and technical difficulties delayed his advance until the afternoon of 7 April. Around 1 o’clock, Du Pont ordered the squadron forward in line- ahead formation, with the Weehawken, Passaic, Montauk, and Patapsco in the lead, followed by the New Ironsides and a second squadron consisting of the Catskill, Nantucket, Nahant, and Keokuk.

At an average speed of three knots, it was one of the slower charges in naval history, but a little before 3 o’clock Captain John Rogers of the Weehawken signalled ‘obstructions ahead’. A few moments later, he and the officers in the pilot house puzzled over what they thought was the faint sound of music.

It was music. The band at Fort Sumter was playing as the garrison, regimental, and state flags were run up the pole a little before 3 o’clock. A few minutes later, a gun from Fort Moultrie started the engagement. This was quickly joined by the remaining guns of Fort Moultrie, those of Fort Beauregard, Battery Bee, and, at 3:03, by a volley from Fort Sumter and Battery Cummings.

Captain Rogers, the focus of such efforts, could feel the vibrations from rounds striking the turret below him, while columns of water bracketed the vessel. But at that moment he had a more pressing problem.

The obstructions, a double line of floating barrels, lay ahead. The plan had been to steam past Fort Sumter and attack the fort’s less defended north-west wall. To do so, however, meant running the floating barricade.

Rogers stared at the line through his field glasses, and when a nearby explosion, which he assumed was a torpedo, lifted the boat a little out of the water, he made up his mind and ordered the vessel to turn to port and come to a stop. ‘The appearance was so formidable’, he later reported to Du Pont, ‘that upon deliberate judgment I thought it right not to entangle the vessel in obstructions which I did not think we could have passed through.’

The attack falters

Rogers’ actions had a ripple effect on the ironclads behind him, bringing them all to a halt 800 yards from Fort Sumter.

While the four lead monitors began to engage the fort with their heavy guns, Du Pont’s flagship was having problems. The rudder design on the recently built New Ironsides had reportedly made the cruiser difficult to manage in the restricted tidal waterways. The Admiral was to discover this first-hand when, about 20 minutes before the firing started, the vessel was forced to come to a stop and throw out its anchor to prevent it running aground.

The ironclads behind the flagship came to a halt, and waited for the armoured cruiser to get under way again. Even simply crawling forward proved too difficult, and the anchor had to be let go once more to prevent a disaster.

With the firing about Fort Sumter growing, Du Pont gave an unusual command: ‘Disregard the motions of the commander-in-chief.’ The signal sent the second squadron of ironclads steaming past the Admiral, each anxious to bring their guns to bear in support of their comrades.

By 3:45, the remaining ironclads had come into action, including the New Ironsides, which could get no closer than 1,000 yards from Fort Sumter. From their vantage-point, the monitor captains could see their rounds striking the walls in bursts of pulverised brick and dust that added to the cloud forming over the fort.

Soon pockmarks and fissures began appearing on the eastern and north-eastern walls, but these came at a price. Both the Patapsco and the Passaic had lost a gun, and both had turret rotation issues after being repeatedly struck. On the Weehawken, Captain Rogers reported that hits on the turret from heavy shot sheered bolts and sent the heads ricocheting about the interior as secondary projectiles.

Captain Percival Drayton of the Passaic and his helmsman experienced far worse. They nearly lost their lives when a rifle bolt hit the top edge of the turret, buckling every plate, and ricocheted into the armoured pilot house, leaving a 2½-inch deep indentation of the bolt’s profile in the side of the structure. ‘The blow was so severe,’ Drayton recalled, ‘as to considerably mash in the pilot house, bend it over, open the plates, and squeeze out the top.’

Were the fort’s guns not peril enough, around 4 o’clock a burst of signals came from the New Ironsides, which Du Pont had attempted to move closer to the fort. The warnings were too late and the flagship collided with the Catskill and Nantucket.

While the trio emerged with minor damage, it was clear that the New Ironsides would play little part in the battle, and a few minutes later the vessel fired its only shots of the engagement, a frustrated long-range broadside at Fort Moultrie.

Inside the fort

In Fort Sumter, the floors trembled when rounds exploded against the structure, and the gun crews on the eastern wall were rattled when a 15-inch round pierced a second-floor gun port and exploded in an empty casemate.

There was, however, little time for more than a passing note of such matters. The hollow thumps of three 10-inch coastal mortars, blindly launching shells filled with melted iron over the walls at the fleet beyond, was supplemented by the fire of 36 cannon along the eastern and north-eastern walls, all of which were operating at a frantic pace: close to half- a-dozen times a minute at one point.

For these gun crews, the scene had quickly devolved into cannon discharges, the rumbling of rounds exploding against the fort, and the shouts of their commanders. In the background, the gaps in this cacophony were filled by the concussion of the monitors’ guns, the occasional ringing of pierced smokestacks, and the sound of howling ricochets that sprayed the nearby waters and littered the decks of the Union vessels with shell fragments.

Suddenly, the violent chorus came to a pause. A well-aimed round carried away the Nantucket’s whistle, bringing forth a shrieking rush of steam and a loud cheer from the defenders.

Crowded channel

One of the last to arrive on the scene, Captain Alexander Rhind of the Keokuk, found a crowded channel before him. It was clear that the attack had not gone as planned. The floating obstacles were still intact and the fleet had responded by positioning itself along the east and north-east face of the fort. Here they were shifting their positions back and forth to throw off the enemy gunners.

This logjam, combined with the confines of the channel and the strong current, forced Rhind to take a position slightly in front of the Union flotilla, some 700 yards from the fort.

While Keokuk’s ‘advance was characterised by more boldness than had hitherto been shown by any of the enemy fleet’, Rhind’s position near the rope barricade placed him in a crossfire between Fort Sumter, Fort Moultrie, and Battery Bee. For the next 30 minutes, a stream of rifle bolts and solid shot hammered the Keokuk, creating a dancing set of sparks on the ironclad’s hull as the rounds found their mark.

The lifeboats disappeared in a whirlwind of wooden debris as 10- and 7-inch solid shot punched holes through the turrets, disabling the guns and spraying the interior with metal shards.

More importantly, a number of rounds had penetrated at the waterline, and one in particular, a 117-pound bolt from a Brooke rifle, a coastal defence gun, had left a ragged 2-foot by 6-foot hole.

With the warship rapidly taking on water, Rhind ordered the gun crews out of the turrets and managed to limp away, having been struck more than 70 times, with many rounds piercing the vessel’s armour.

Recall

With the Keokuk retiring, and unable to navigate the New Ironsides into the desired firing position, Du Pont signalled the recall at 4.30pm.

Sunset was a few hours away and the flagship still faced a tricky return back to the previous anchorage. There Du Pont would resupply, develop a plan to bring the flagship closer to the fort, and attack again the next morning. Even so, it would not be until almost 5.30pm that the last monitor broke off contact and departed for the rendezvous point.

When Du Pont met with his captains at the anchorage that evening, he quickly realised that his force was in no condition to continue the assault. Although the fleet had only been closely engaged for an hour, the damage was devastating.

The leaks on the riddled Keokuk had been temporarily stopped and the pumps were just keeping it afloat. The Nahant, Patapsco, Nantucket, and Passaic had all lost use of a gun or had experienced turret damage that impaired their abilities.

The other vessels had not been disabled, but after looking at the damage Du Pont was convinced ‘that in all probability in another 30 minutes they would have been likewise disabled’. Every vessel had been struck more than a dozen times, and most far more, with sheered bolts and ruptured iron plates showing everywhere. Fortunately, the number of casualties was small, with only one dead and a score of wounded.

At that moment, there was little for the Admiral to do but tend to his injured fleet. The next morning the seas became rougher and the Keokuk sank in shallow water up to its smokestack and turrets. It would still be several days before Du Pont repaired his damage and departed, and during this time he wrote to General David Hunter, in command of the Union Army on James Island, calling off the operation. ‘I attempted to take the bull by the horns,’ the Admiral confided in him, ‘but he was too much for us.’

Confederate victory

For the defenders of Charleston, it was a major victory, and as the Union ironclads withdrew, a chorus of celebratory shouts and jeers followed them.

Casualties had been light, and although Fort Sumter had been badly damaged in several places, it was not enough to impede the effectiveness of the fort.

For Beauregard in particular, it was a vindication of his defensive strategy. He had focused his guns on a small stretch of waterway, and with the aid of ranging buoys and professional crews, the defenders were able to fire an astounding 2,200 rounds over the two-and-a-half-hour battle, compared to 136 from Du Pont’s fleet.

Together with the floating obstructions, the armament of the outer forts had proved enough to halt the Union’s armoured spearhead. The achievement was even greater given that many of the heaviest guns near the town had not been brought to bear.

‘Therefore, it may be accepted, as shown,’ Beauregard deduced, ‘that these vaunted monitor batteries, though formidable engines of war, after all are not invulnerable nor invincible, and may be destroyed or defeated by heavy ordnance properly placed and skilfully handled. In reality, they have not materially altered the military relations of forts and ships.’

This assessment is sound and enduring. Whatever the prevailing technology of protection and gunpower, the ship always has the grave disadvantage that she must carry both, that she constitutes an unstable firing platform, that her complex technical apparatus is highly vulnerable, and that she presents a very clear target from land. The fixed-position coastal gunner holds all the cards unless an overwhelming weight of naval gunfire can be brought to bear. •

Michael Laramie is a military-history writer and the author of six books on colonial America and the US Civil War. His next work, Gunboats, Muskets, and Torpedoes: Coastal South Carolina, 1861-1865, will be released in autumn 2022.