<Li> Lt. Gen . John C. Pemberton, CSA </Li> <P> Vicksburg was strategically vital to the Confederates . Jefferson Davis said, "Vicksburg is the nail head that holds the South's two halves together ." While in their hands, it blocked Union navigation down the Mississippi; together with control of the mouth of the Red River and of Port Hudson to the south, it allowed communication with the states west of the river, upon which the Confederates depended extensively for horses, cattle and reinforcements . The natural defenses of the city were ideal, earning it the nickname "The Gibraltar of the Confederacy ." It was located on a high bluff overlooking a horseshoe - shaped bend in the river, De Soto Peninsula, making it almost impossible to approach by ship . North and east of Vicksburg was the Mississippi Delta (sometimes known as the Yazoo Delta), an area 200 miles (320 km) north to south and up to 50 miles (80 km) across, which has been described by geographer Warren E. Grabau as an "astonishingly complex network of intersecting waterways", some of which were navigable by small steamboats . The regions between modern rivers and bayous formed closed basins called backswamps, of which Grabau judged, "Whether permanently flooded or not, the backswamps were, for all practical purposes, untamed wildernesses, utterly impassable by a man on horseback or by any form of wheeled vehicle, and very difficult even for a man on foot ." About twelve miles (19 km) up the Yazoo River were Confederate batteries and entrenchments at Haynes Bluff . The Louisiana land west of Vicksburg was also difficult, with many streams and poor country roads, widespread winter flooding, and it was on the opposite side of the river from the fortress . </P> <P> The city had been under Union naval attack before . Admiral David Farragut moved up the river after his capture of New Orleans and on May 18, 1862, demanded the surrender of Vicksburg . Farragut had insufficient troops to force the issue, and he moved back to New Orleans . He returned with a flotilla in June 1862, but their attempts (June 26--28) to bombard the fortress into surrender failed . They shelled Vicksburg throughout July and fought some minor battles with a few Confederate vessels in the area, but their forces were insufficient to attempt a landing, and they abandoned attempts to force the surrender of the city . Farragut investigated the possibility of bypassing the fortified cliffs by digging a canal across the neck of the river's bend, the De Soto Peninsula . On June 28, Brig. Gen. Thomas Williams, attached to Farragut's command, began digging work on the canal by employing local laborers and some soldiers . Many of the men fell victim to tropical diseases and heat exhaustion, and the work was abandoned by July 24 . (Williams was killed two weeks later in the Battle of Baton Rouge). </P> <P> In the fall of 1862, Maj. Gen. Henry W. Halleck was promoted from command of the Western Theater to general - in - chief of all Union armies . On November 23, he indicated to Grant his preference for a major move down the Mississippi to Vicksburg; in Halleck's style, he left considerable initiative to design a campaign, an opportunity that the pugnacious Grant seized . Halleck has received criticism for not moving promptly overland from Memphis, Tennessee, to seize Vicksburg during the summer when he was in command on the scene . He believed that the Navy could capture the fortress on its own, not knowing that the naval force was insufficiently manned with ground troops to finish the job . What might have achieved success in the summer of 1862 was no longer possible by November because the Confederates had amply reinforced the garrison by that time . Also reliable navigation on the river was seasonal, and the natural fall in the level of the river during the fall and winter months limited the utility of shipping, the usable draft of riverboats, and the quantity of men, supplies, and equipment, they could transport . </P>

The union admiral that led the campaign against new orleans