Vicksburg Campaign - Background

Background

Vicksburg was strategically important 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), a practically impenetrable swamp which is 200 miles (320 km) north to south and up to 50 miles (80 km) across. 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.

The city had been under Union naval attack before. Admiral David Farragut moved up the river after he captured 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).

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.

Grant's army marched south down the Mississippi Central Railroad, making a forward base at Holly Springs. He planned a two-pronged assault in the direction of Vicksburg. His principal subordinate, Maj. Gen. William T. Sherman, was to advance down the river with four divisions (about 32,000 men) and Grant would continue with the remaining forces (about 40,000) down the railroad line to Oxford, where he would wait for developments, hoping to lure the Confederate army out of the city to attack him in the vicinity of Grenada, Mississippi.

On the Confederate side, forces in Mississippi were under the command of Lt. Gen. John C. Pemberton, an officer from Pennsylvania who chose to fight for the South. Pemberton had approximately 12,000 men in Vicksburg and Jackson, Mississippi, and Maj. Gen. Earl Van Dorn had approximately 24,000 at Grenada.

Meanwhile, political forces were at work. President Abraham Lincoln had long recognized the importance of Vicksburg; he wrote "Vicksburg is the key. The war can never be brought to a close until the key is in our pocket." Lincoln also envisioned a two-pronged offensive, but one up and down the river. Maj. Gen. John A. McClernand, a War Democrat politician, had convinced Lincoln that he could lead an army down the river and take Vicksburg. Lincoln approved his proposal and wanted Maj. Gen. Nathaniel P. Banks to advance up river from New Orleans at the same time. McClernand began organizing regiments, sending them to Memphis. Back in Washington, D.C., Halleck was nervous about McClernand and gave Grant control of all troops in his own department. McClernand's troops were split into two corps, one under McClernand, the other under Sherman. McClernand complained but to no avail. Grant appropriated his troops, one of several maneuvers in a private dispute within the Union Army between Grant and McClernand that continued throughout the campaign.