Siege of Vicksburg - Background

Background

After crossing the Mississippi River south of Vicksburg at Bruinsburg and driving northeast, Grant won battles at Port Gibson and Raymond and captured Jackson, the Mississippi state capital on May 14, 1863, forcing Pemberton to withdraw westward. Attempts to stop the Union advance at Champion Hill and Big Black River Bridge were unsuccessful. Pemberton knew that the corps under Maj. Gen. William T. Sherman was preparing to flank him from the north; he had no choice but to withdraw or be outflanked. Pemberton burned the bridges over the Big Black River and took everything edible in his path, both animal and plant, as he retreated to the well-fortified city of Vicksburg.

The Confederates evacuated Hayne's Bluff, which was occupied by Sherman's cavalry on May 19, and Union steamboats no longer had to run the guns of Vicksburg, now being able to dock by the dozens up the Yazoo River. Grant could now receive supplies more directly than by the previous route, which ran through Louisiana, over the river crossing at Grand Gulf and Bruinsburg, then back up north.

Over three quarters of Pemberton's army had been lost in the two preceding battles and many in Vicksburg expected General Joseph E. Johnston, in command of the Confederate Department of the West, to relieve the city—which he never did. Large masses of Union troops were on the march to invest the city, repairing the burnt bridges over the Big Black River; which Grant's forces crossed on May 18. Johnston sent a note to his general, Pemberton, asking him to sacrifice the city and save his troops, something Pemberton would not do. (Pemberton, a Northerner by birth, was probably influenced by his fear of public condemnation if he abandoned Vicksburg.)

Pemberton, trying to please Jefferson Davis, who insisted that Vicksburg and Port Hudson must be held, and to please Johnston, who thought both places worthless militarily, had been caught in the middle, a victim of a convoluted command system and his own indecisiveness. Too dispirited to think clearly, he chose to back his bedraggled army into Vicksburg rather than evacuate the city and head north where he might have escaped to campaign again. When he chose to take his army into Vicksburg, Pemberton sealed the fate of his troops and the city he had been determined to defend.

— Vicksburg, Michael B. Ballard.