All such were depleted to the minimum necessary to hold their positions as a guard against blockade runners; where they could not do this their positions were abandoned altogether.

In this way ten thousand men were added to the Army of the James from South Carolina alone, with General Gillmore in command.

It was not contemplated that General Gillmore should leave his department; but as most of his troops were taken, presumably for active service, he asked to accompany them and was permitted to do so.
Officers and soldiers on furlough, of whom there were many thousands, were ordered to their proper commands; concentration was the order of the day, and to have it accomplished in time to advance at the earliest moment the roads would permit was the problem.
As a reinforcement to the Army of the Potomac, or to act in support of it, the 9th army corps, over twenty thousand strong, under General Burnside, had been rendezvoused at Annapolis, Maryland.

This was an admirable position for such a reinforcement.

The corps could be brought at the last moment as a reinforcement to the Army of the Potomac, or it could be thrown on the sea-coast, south of Norfolk, in Virginia or North Carolina, to operate against Richmond from that direction.