The change of command had been forecast weeks before. But the switch was made official on February 9, 1865. Major-General John Foster issued General Orders No. 15 for the Department of the South from Hilton Head that day:
Having been granted a leave of absence, on account of disability from wounds, I hereby transfer the command of this department during my absence to Maj. Gen. Q.A. Gillmore, U.S. Volunteers, in accordance with orders from the War Department.
Gillmore posted General Orders No. 16 announcing his assumption, temporary assumption, of command.
Foster had suffered a hard fall from his horse the previous winter, while serving in Tennessee. That, along with effects of other, older wounds, took a toll on the forty-one year old general. Earlier he’d worked a request, by way of his wife, to secure a leave of absence. One historian has cast this as a move “in order to save face….” But there seems to be little weight for that inference.
Major-General William T. Sherman had recognized Foster’s impairment, starting on the night after Fort McAllister fell. When Foster’s department was placed under Sherman’s military division, the two continued to work together. Sherman avoided replacing Foster during January when authorities in Washington had offered several able replacements. Instead, Sherman worked with Foster, launched the march into South Carolina, and was issuing instructions to his subordinate right up until the day of the change in command. In fact, even after the change, Sherman still addressed correspondence to Foster (particularly on February 24 and March 12!). The simple explanation is Foster was physically impaired at that point. And was thus not able to share the laurels that were to come.
However, this change came at a critical time. In a very thorough (better than Gillmore left on his departure the previous spring, I might add) letter, Foster described the operational and tactical situation. Referencing Sherman’s written instructions (and recall those of February 7 still had not reached the coast), Foster explained:
General Sherman’s written instructions may be modified in execution if the circumstances warrant it; for instance, if the enemy show a disposition to evacuate Charleston he may be felt strongly, and if the evacuation actually takes place the works are to be occupied and the diversion in Bull’s Bay may not then be made. Secondly. After carrying out the instructions regarding the operation at Bull’s Bay, if, in the judgment of the commander of the department, an additional operation may be attempted on Sullivan’s Island, as the admiral desires, he may undertake it if circumstances be favorable. This must not, however, be to the prejudice of anything specially directed by General Sherman.
As for ongoing operations, Foster described each in detail. Brigadier-General John Hatch was over the Salkehatchie-Combahee with orders to pursue the Confederates along the railroad. “This ought to be done as far as the Ashepoo if possible, and under very favorable circumstances to the Edisto.”
Brigadier-General Henry Prince, at Pocotaligo, held detachments from Sherman’s army to guard communications with Sherman’s columns. While Hatch might be withdrawn when Sherman reached the vicinity of Columbia, Prince’s base was to be maintained indefinitely, by order of Lieutenant-General Ulysses S. Grant.
Foster continued, as he knew Gillmore’s attention would be focused on Charleston:
As far as operations in Charleston Harbor is concerned, the commander of the department may co-operate with the admiral in any way that he may judge proper, provided the written instructions be first fully carried out. General Sherman did not favor any serious operation about Charleston Harbor, but was willing to yield his objections if the commanding officer, after carrying out his essential directions, judged he had an opportunity favorable enough to warrant the risk of a serious attack. General Sherman attached more importance to the flank movement at Ball’s Bay and Georgetown. Major Gray informed me that General Sherman desired the operation at Bull’s Bay to be made six days from that day (the 8th instant). The force for this is assembled at the Stono.
The date set for the demonstration at Bull’s Bay is rather important to set in context. On the day Foster and Gillmore changed the guidon, Brigadier-General Alexander Schimmelfennig was preparing for a joint operation into the Stono River. The objective was to demonstrate against James and John’s Islands. This operation was timed to work with another naval operation on the North Edisto. Foster had sent instructions for that operation on February 6. And due to Sherman’s notes on February 8, complaining about delays due to the bad roads, Foster intended to continue those demonstrations. The intent was to make feints on one side of Charleston before withdrawing the troops to land on the other side at Bull’s Bay.
The problem here was there being only so many troops in the department to perform all these demonstrations. Hatch had about 3,500 men. Schimmelfennig could scrape together about 1,000. By removing troops from Schimelfennig and pulling others from around Hilton Head, the Federals could put 1,300 men under Brigadier-General Edward Potter at Bull’s Bay. It is not clear from the record if Foster or Gillmore decided Bull’s Bay would have priority. But regardless the abrupt change caused problems with the navy.
While Sherman appeared to remain aloof from the change in command, Rear-Admiral John Dahlgren was unsettled to say the least. On February 10, one of Dahlgren’s officers returned from Hilton Head with news,
… General Foster told him that the Stono must be over and the troops must be going to Bull’s Bay by this time. Also, that General Gillmore had taken command. How vexatious! If General Gillmore had left a note with Captain Reynolds, saying what he designed to do, it would have been easy enough.
Dahlgren was not happy with the prospect of another operation with the general. The two had not parted on cordial terms the previous spring. Dahlgren hung the failure to take Charleston earlier in 1863 on Gillmore. Now Gillmore was back to share in the laurels of the capture of the city.
While Foster departed having given Gillmore a fair appreciation for the situation, there is one thing he retained and which would serve to inhibit operations that followed. Foster had possession of the cypher used by Sherman to encrypt messages. This was the same cypher given to Dahlgren in January. Gillmore was not part of that “circle of friends”… if I may. On February 13, when Sherman’s orders written on February 7 finally arrived at the coast, Gillmore couldn’t read the message. He had to beg Dahlgren for assistance.
The good news, however, was that the end at Charleston was near. These personal issues and counter-marches would not stand in the way of eventual success. The matter was at that time being decided well to the north of Charleston.
(Citations from OR, Series I, Volume 47, Part II, Serial 99, pages 367 and 369; ORN, Series I, Volume 16, page 367; E. Milby Burton, The Siege of Charleston: 1861-1865, Columbia, SC: University of South Carolina Press, 1970, page 314.)