On April 21, 1864, Rear-Admiral John Dahlgren passed a summary report to Secretary of the Navy Gideon Wells. As Dahlgren had at other occasions since September of the previous year, the commander of the South Atlantic Blockading Squadron offered operational options to employ the forces then outside Charleston, South Carolina (and note that Dahlgren was in Washington at the time, and not with the fleet off South Carolina):
Sir: As the demands of the public service elsewhere will prevent the detail of more iron-clads for service at Charleston, which will necessarily postpone any serious attack on the interior defenses of the harbor, I directed combined operations to would suggest that be the occupation of Long Island, with the view of an attack on the works of Sullivan’s Island, to be prosecuted as far as the force ashore and afloat may permit. If Sullivan’s Island can be occupied, it would enable the iron-clads to maintain position in the harbor permanently, and in the end to drive the rebels from Charleston.
And for emphasis, Dahlgren’s suggestion to operate against Sullivan’s Island was not a new proposal. Dahlgren had pressed for such since the fall of Morris Island. But nothing so concrete as to commit a plan to paper.
As with other similar suggestions, Wells referred the matter over to the Secretary of War, Edwin Stanton, for comment. In those earlier events, Stanton had turned to Major General Henry Halleck for a response. And Halleck had, like Dahlgren, remained non-committal. And neither Halleck or Dahlgren would leave any remark which the opposite branch of service might interpret as a reluctance to support further operations.
But this was April 1864. Stanton did not turn to Halleck, but rather to Lieutenant-General U.S. Grant. For his response, on April 24, Grant requested direct input from Major-General Quincy Gillmore, who was at that time preparing to leave Charleston.
General: Herewith I send you copy of letter from Admiral Dahlgren to the Secretary of the Navy, and from the latter to the military authorities, recommending certain movements near Charleston, S.C. The letters explain themselves. Please read them and send me your views on the proposed movements. Not knowing the situation of affairs about Charleston, and particularly since the withdrawal of so many of your forces, I can give no specific directions. I would state, however, that it will be of great advantage to us if the force at Charleston can be safely employed in keeping up a demonstration that will force the enemy to keep large numbers there to watch their movements.
While giving some consideration to resuming some operations against Charleston, Grant’s mind seemed fixed. Charleston was not on his list of objectives. There was no room offered for Gillmore to even suggest more troops. In Grant’s view, any operations would remain limited to demonstrations. And, reading between the lines, the reason for Gillmore’s input was to qualify, and quantify, the response back to the Navy.
Grant was not in favor of non-specific plans against elusive goals. Nor was Grant willing to curtail or compromise his larger scheme of operations for the chance to settle a score at Charleston. The cradle of secession was no longer a top objective.
For what it was worth, Halleck offered his opinion on the matter:
If the iron-clads and the large number of troops off Charleston for the last year could not take and hold Sullivan’s Island, how can they expect to do it with forces diminished more than one-half? Moreover, if taken, it would simply result in the loss from active service of 5,000 troops to garrison it, without any influence upon the coming campaign. It will require 60,000 men three months to take Charleston. The capture of Sullivan’s Island would not have much influence upon the siege of that place, as it can be conducted with greater advantage from other points. I am satisfied that Admiral Dahlgren’s letter was intended simply as an excuse in advance for the inability of the iron-clads to accomplish anything against Charleston.
Give Halleck credit, as he appeared to best characterize the nature of Dahlgren’s original letter starting this chain. With no ironclad reinforcements, Dahlgren was not ready to “damn the torpedoes.”
But at this point, I have to ask why Halleck had not expressed this view five months earlier?
(Citations from OR, Series I, Volume 35, Part II, Serial 66, pages 64, 67-8.)