Up to this time we had not communicated with our fleet. From the signal station at the rice mill our officers had looked for two days over the rice fields and salt marsh in the direction of Ossabaw Sound, but could see nothing of it. But while watching the preparations for the assault on Fort McAllister we discovered in the distance what seemed to be the smoke-stack of a steamer, which became more and more distinct, until about the very moment of the assault she was plainly visible below the fort, and our signal was answered. As soon as I saw our colors fairly planted upon the walls of McAllister, in company with General Howard I went in a small boat down to the fort and met General Hazen, who had not yet communicated with the gun-boat below, as it was shut out to him by a point of timber. Determined to communicate that night, I got another small boat and a crew and pulled down the river till I found the tug Dandelion, Captain Williamson, U. S. Navy, who informed me that Captain Duncan, who had been sent by General Howard, had succeeded in reaching Admiral Dahlgren and General Foster, and that he was expecting them hourly in Ossabaw Sound. After making communications to those officers, and a short communication to the War Department, I returned to Fort McAllister that night, and before daylight was overtaken by Major Strong, of General Foster's staff, advising me that General Foster had arrived in the Ogeechee, near Fort McAllister, and was very anxious to meet me on board his boat. I accordingly returned with him, and met General Foster on board the steamer Nemaha; and after consultation determined to proceed with him down the sound in hopes to meet Admiral Dahlgren. But we did not meet him until we reached Wassaw Sound, about noon. I there went on board the admiral's flag-ship, the Harvest Moon, after having arranged with General Foster to send us from Hilton Head some siege ordnance and some boats suitable for navigating the Ogeechee River. Admiral Dahlgren very kindly furnished me with all the data concerning his fleet and the numerous forts that guarded the inland channels between the sea and Savannah. I explained to him how completely Savannah was invested at all points, save only the plank road on the South Carolina shore, known as the Union Causeway, which I thought I could reach from my left flank across the Savannah River. I explained to him that if he would simply engage the attention of the forts along Wilmington Channel, at Beaulieu and Rosedew, I thought I could carry the defenses of Savannah by assault as soon as the heavy ordnance arrived from Hilton Head. On the 15th the admiral carried me back to Fort McAllister, whence I returned to our lines in the rear of Savannah.
Having received and carefully considered all the reports of division commanders, I determined to assault the lines of the enemy as soon as my heavy ordnance came from Port Royal, first making a formal demand for surrender. On the 17th, a number of 30-pounder Parrott guns having reached King's Bridge, I proceeded in person to the headquarters of Major-General Slocum, on the Augusta road, and dispatched thence into Savannah, by flag of truce, a formal demand for the surrender of the place; and on the following day received an answer from General Hardee refusing to surrender.
In the meantime further reconnaissances from our left flank had demonstrated that it was impracticable or unwise to push any considerable force across the Savannah River, for the enemy held the river opposite the city with iron-clad gun-boats, and could destroy any pontoons laid down by us between Hutchinson's Island and the South Carolina shore, which would isolate any force sent over from that flank.