". . . .Old Peter was obliged to serve three masters -- Davis, Seddon, and Lee -- who saddled him with three separate, simultaneous, and sometimes incompatible assignments: 1) the protection of the national capital, threatened by combinations of forces superior to his own, 2) the gathering of supplies in an area that had been under Federal domination for nearly a year, and 3) the disposition of his troops so as to be able to hurry them back to the Rappahannock on short notice . . . The wonder, under such conditions as obtained, was not that he failed in part, but that he succeeded to any degree at all in fulfilling these divergent expectations."
Longstreet was never able to mount the offensive operations against, especially, Suffolk that he had hoped for, mainly because the garrison inside the Federal fortifications was stronger than any force Longstreet could bring against it, even if he could have soothed the divergent personalities of his newly inherited regional commanders or somehow made sure all his above three missions were carried out. As a result the entire operation was mostly a large scale foraging mission, no less important to the army than a victory in battle, but not nearly as strewn with laurels.
Source: The Civil War: A Narrative
Commentary
In the early part of 1863 the Army of Northern Virginia found itself in somewhat desperate straights. The main thing was the severe lack of supplies, but also on Lee's and President Davis' minds were the Federal troops now building strongholds in southern Virginia, near Suffolk and Norfolk, which could prove to threaten both Lee's rear and Richmond itself.
James Longstreet along with most of his corps was dispatched to this area and given the primary goal of gathering supplies and sending them back to Lee's army. In the course of carrying out this goal, other ones came into being, most notably keeping the Federals in their garrisons to allow his men to go about their work unmolested.
To help him facilitate his goals, he was appointed by Seddon to command of the Department of Virginia and North Carolina, formerly the three separate divisions of Richmond, Southern Virginia, and North Carolina in addition to the independant Cape Fear River District. These separate commands, under wildly divergent commanders who often did not get along, would prove to be a consistent thorn in Longstreet's side. But, above all, Longstreet's greatly problem during his first try at independant command was that he was constantly pulled in separate directions by those above him.
Shelby Foote, in his mammoth work on the Civil War, probably stated it best: