150 years ago: Fort McAllister again! Why was that post so important?

On this day (March 3) in 1863, once again the Navy sortied to pester the Confederates at Fort McAllister.  Yes, the sixth time in just under a year.  This time the Navy brought forward three of its monitors new monitors to test the fort – USS Passaic, USS Nahant, and USS Patapsco. The USS Montauk, still being repaired from the torpedo encounter of February 28, also provided support from a fair distance.  These four monitors, all of the Passaic-class which would eventually grow to ten in number, represented the largest concentration of the type to date.

In addition to the monitors, the mortar schooners USS C.P. Williams, USS Norfolk Packet, and USS Para, towed by the steamers USS Seneca, USS Dawn, and USS Wissahickon respectively, supported the attack.  Captain Percival Drayton commanded this force.

As morning came to the salt marshes along the Ogeechee River, the Passaic pressed upstream to within 1,200 yards of Fort McAllister.  The Nahant and Patapsco stopped just behind the lead monitor. The mortar schooners laid back with the Montauk. At around 9 A.M. Drayton gave the order to commence firing.  The force kept up a steady fire for eight hours.   And of course the fort returned fire.  For all the expended shot and shell, casualties were limited to a few wounded.  The Confederate fort reported damage to carriages and displaced sand, but that was easily repaired.  The monitors suffered some bent plates and popped rivets, but all else was in order.  In short, a somewhat anti-climatic and inconclusive affair.  (Rob provided a more detailed account of the action on the Civil War Navy Sesquicentennial blog.)

Both sides digested lessons from this concentrated attack.  The Navy noted more deficiencies with armament but remained confident in the invulnerability of the monitors to shore fire.  The Confederates, while somewhat frustrated at the ineffectiveness of their shot to penetrate, were content that monitors could not reduce earthwork forts.  The Navy’s practice of spinning turrets aft to load, then forward to fire, allowed the defenders a predictable interval between incoming rounds.  This accounted for the low casualties.

Each side offered a wealth of details in these after-action reports relating to ordnance, armor, and fortifications.  Such are the details I love to weigh, and you’ll likely read about them in other posts.  But today I am thinking more to the broader aspects of the actions at Fort McAllister, in these first three months of 1863.

No doubt the Federal operations against the fort were a function of the disruption of trade caused by Confederate privateers.  With the likes of the CSS Florida and Alabama already on the loose, the Navy did not wish for the Nashville-Rattlesnake to pile on more woes.  But of course the railroad crossing upstream was an alluring target.  Yet the Federal activity was not directed towards a strategic objective, but rather operational – to seal off one more inlet for the blockade.

In other posts I have discussed the undermanned and under-equipped defense established by General P.G.T. Beauregard across South Carolina and Georgia, and for good measure covering Florida. Likewise, departments adjacent to Beauregard’s prepared to meet a growing Federal Army-Navy threat from the Atlantic with meager resources.  To the north Brigadier-General W.H.C. Whiting also felt the pressure while arranging the defense of his charge – Wilmington and the Fear River.  In correspondence with Beauregard in January, Whiting said:

I have just received your telegrams relative to strategic matters. I do not think Raleigh enters into the matter for the present, nor do I regard either of them in the light of cities; that is to say, so much property. The enemy having already possession of Tybee and Pulaski, I cannot regard Savannah as of any strategic importance. It is a place, to be sure, and one which we hope to hold; but it is an extremity, not an artery (emphasis added). To me it appears plain that for the winter the main operations of the enemy will take place in North Carolina, whether their object be Richmond or Charleston. The enemy will not divide his attack on all three of the places you suggest; he will take one or the other…. Look at the map.

Whiting again dismissed Savannah’s importance in the aftermath of the January 27 – February 1 attacks on Fort McAllister:

The movements of the enemy puzzle me. Unless they are gone mad they cannot mean to attack Savannah. It could have no possible effect on the war if they were to take it. Wilmington, Charleston, or Mobile is worth forty Savannahs to us and to them. They may mean to try and withdraw troops from here and North Carolina for they still have a very heavy force at Beaufort; but that should be resisted. I fear Beauregard will take alarm and recall his troops from here.

And indeed Beauregard did take alarm, sensing the Fort McAllister attacks as a precursor to a heavy assault on Charleston.  On February 12, he not only recalled troops temporally posted to Wilmington, but also asked for the return of a rifled 42-pdr gun (and a 10-inch columbiad redirected in shipment originally intended for Charleston).   Two brigades of troops then shifted back to Charleston (although small brigades in terms of overall strength).

Consider the shifting of forces in context.  Beauregard pulled two brigades.  That gave Whiting less to confront threats.  So he fired off requests to his superiors.  That of course was the “new,” although temporary, command of Lieutenant-General James Longstreet – the Department of Virginia and North Carolina.  On March 15, Longstreet’s answer to Whiting’s request was less than hoped for:

… You will need more troops for the defense of Wilmington when there is a probability of attack there, but I do not agree with you in your desire to mass troops there in order to have them for the attack.  On the contrary, I think that every soldier should be kept busy.  If the troops at Wilmington are not constantly employed there they should be in the field, annoying the enemy whenever and wherever it may be done…. If we hold isolated positions by detachments the enemy will at his pleasure move upon the different points and take them in detail….

In perspective, two different approaches to defending the coastline.  Both at odds due to the shifting of troops.

I won’t go as far to say the Navy’s persistent ironclad attacks on Fort McAllister was the sole reason for these troop shifts, and straining of the Confederate defenses.   But with nearly every week another visible threat to the far left anchor of his defensive line, Beauregard remained very sensitive.  If nothing else, the Navy’s operational concern on the Ogeechee had a ripple effect at a higher level on the Confederate side.

(Citations from OR, Series I, Volume 18, Serial 26, pages 830, 868 and 920.)