Daniel Ammen, Confederate Military History, a library of Confederate States Military History: Volume 7.2, The Atlantic Coast
Clement Anselm Evans, Ed.

For a long period the only ports or inlets that remained to the Confederates admitting a vessel of twelve feet draught were Charleston and Wilmington; the latter, however, had two entrances far apart, which made practically a double blockading force necessary. It was of the greatest importance to prevent the arrival of supplies, and however many blockade-runners were destroyed, it was not to be denied that many vessels arrived at and departed from those ports, and would continue to do so until the National forces actually held the entrances.

The usual blockade force off Charleston numbered twenty vessels. Preceding the bombardments of Fort Fisher, thirty to forty vessels blockaded the two entrances to Wilmington, yet, with the utmost vigilance on their part, a great number of vessels got in and out. Hence the great anxiety of the Navy Department to gain possession of the entrances to those harbors. An official letter to Rear-Admiral Farragut, dated September 5, 1864, appointing him to the command of a naval force designed to attack the defences of Cape Fear liver, states that since the winter of 1862 the Navy Department had endeavored ‘to get the consent of the War Department to a joint attack upon the defenses of Cape Fear Liver, but they had decided that no troops could be spared for the operation. Lieutenant-General Grant had, however, recently given the subject his attention, and thought an army force would be ready to co-operate on the 1st of October.’

For strategic purposes the force was to assemble at Port Royal, and in addition to the force to assemble through the direct order of the Department, the admiral was authorized to bring with him all such vessels and officers as could be