The Battle of Vicksburg, or Siege of Vicksburg, was the final significant battle in the Vicksburg Campaign of the American Civil War. In a series of skilled maneuvers, Union Maj. Gen. Ulysses S. Grant and his Army of the Tennessee crossed the Mississippi River and drove the Confederate army of Lt. Gen. John C. Pemberton into defensive lines surrounding the fortress city of Vicksburg, Mississippi. Grant besieged the city from May 18 to July 4, 1863, until it surrendered, yielding command of the Mississippi River to the Union.

Assaults
Grant's optimism grew as he realized he had the city invested. With their backs against the Mississippi and Union gunboats firing from the river, Confederate soldiers and citizens alike were trapped. Grant's troops dug in and started a siege. Pemberton was determined to hold his few miles of the Mississippi as long as possible, hoping for relief from Johnston or elsewhere.
A new problem confronted the Confederates. The dead and wounded of Grant's army lay in the heat of Mississippi summer, the odor of the deceased men and horses fouling the air, the wounded crying for medical help and water. Grant first refused a request of truce, thinking it a show of weakness. Finally he relented, and the Confederates held their fire while the Union recovered the wounded and dead, soldiers from both sides mingling and trading as if no hostilities existed for the moment.
In an effort to cut Grant's supply line, the Confederates attacked Milliken's Bend up the Mississippi on June 7. This was mainly defended by untrained colored troops, who fought bravely with inferior weaponry and finally fought off the rebels with help from gunboats, although at horrible cost; the defenders lost 652 to the Confederate 185. The loss at Milliken's Bend left the rebels with no hope for relief but from the cautious Johnston.
All through June, the Union dug lines parallel to and approaching the rebel lines. Soldiers could not poke their heads up above their works for fear of snipers. It was a sport for Union troops to poke a hat above the works on a rod, betting on how many rebel bullets would pierce it in a given time.
Pemberton was boxed in with lots of inedible munitions and little food. The poor diet was showing on the Confederate soldiers. By the end of June, half were out sick or hospitalized. Scurvy, malaria, dysentery, diarrhea, and other diseases cut their ranks. At least one city resident had to stay up at night to keep starving soldiers out of his vegetable garden. The constant shelling did not bother him as much as the loss of his food. As the siege wore on, fewer and fewer horses, mules, and dogs were seen wandering about Vicksburg. Shoe leather became a last resort of sustenance for many adults.
As the bombing continued, suitable housing in Vicksburg was reduced to a minimum. A ridge, located between the main town and the rebel defense line, provided a diverse citizenry with lodging for the duration. Whether houses were structurally sound or not, it was deemed safer to occupy these dugouts. People did their best to make them comfortable, with rugs, furniture, and pictures. They tried to time their movements and foraging with the rhythm of the cannonade, sometimes unsuccessfully. Because of these dugouts or caves, the Union soldiers gave the town the nickname of "Prairie Dog Village." Since the fighting line was fairly close, soldiers made their way rearward to visit family and friends, a boost to morale.

Siege
One of the major roads into Vicksburg was the Jackson Road. To guard this entrance the 3rd Louisiana Infantry built a large earthen redan, which became known as the 3rd Louisiana Redan. Union troops tunneled under the redan and packed the mine with 2,200 pounds of black powder. The explosion blew apart the Confederate lines on June 25, while an infantry attack made by troops from Maj. Gen. John A. Logan's XVII Corps division followed the blast. Logan's troops led by Col. Jaspar Maltby's 45th Illinois Regiment charged into the crater with ease. They were, however, stopped by rearward Confederate infantry and became pinned down in the crater. Short fuse shells were simply rolled into the crater with deadly results. Union engineers worked to set up casement in the crater in order to extricate the infantry and soon the soldiers fell back to a new defensive line. From the crater left by the explosion on June 25, Union miners worked to dig a new mine to the south. On July 1, this mine was detonated but no infantry attack followed. Pioneers worked throughout July 2 and July 3 to widen the initial crater large enough for an infantry column of four to pass through for future anticipated assaults. However, events the following day negated any further assaults.

Mine explosions
Joseph E. Johnston, the only possibility for a Confederate rescue, felt his force at Jackson was too small to attack Grant's huge army. While Johnston's force was growing (at cost to the rest of the hard-pressed Confederacy), Grant's was growing faster, supplied via the now-open Yazoo River. Johnston, lacking in supplies, stated, "I consider saving Vicksburg hopeless." The Confederate government felt otherwise, asking the cautious Johnston to attack, requests he resisted. Robert E. Lee had remarked that the Mississippi climate in June would be sufficient to defeat the Union attack and he resisted calls to ride to the city's rescue from the Eastern Theater; his Army of Northern Virginia instead invaded the North in the Gettysburg Campaign with the partial objective of relieving pressure on Vicksburg. Finally on July 1, Johnston's relief column began cautiously advancing due west toward Union lines. On July 3 he was ready for his attack, but on July 4, Independence Day, the Union guns were oddly quiet.
On July 3, Pemberton sent a note to Grant, who, as at Fort Donelson, first demanded unconditional surrender. But Grant reconsidered, not wanting to feed 30,000 hungry Confederates in Union prison camps, and offered to parole all prisoners. Considering their destitute state, dejected and starving, he never expected them to fight again; he hoped they would carry home the stigma of defeat to the rest of the Confederacy. In any event, it would have occupied his army and taken months to ship that many troops north.
Surrender was formalized by an old oak tree, "made historical by the event." In his Personal Memoirs, Grant described the fate of this luckless tree:
Although there was more action to come in the Vicksburg Campaign, the fortress city had fallen and, with the capture of Port Hudson on July 8, the Mississippi River was firmly in Union hands and the Confederacy split in two.
The Fourth of July holiday was not celebrated by most of the citizens of Vicksburg until World War II, because of the surrender of the city on July 4.
The works around Vicksburg are now maintained by the National Park Service as Vicksburg National Military Park.

See also

Ballard, Michael B., Vicksburg, The Campaign that Opened the Mississippi, University of North Carolina Press, 2004, ISBN 0-8078-2893-9.
Bearss, Edwin C., The Vicksburg Campaign, 3 volumes, Morningside Press, 1991, ISBN 0-89029-308-2.
Catton, Bruce, Never Call Retreat, Doubleday, 1965, ISBN 0-671-46990-8.
Eicher, David J., The Longest Night: A Military History of the Civil War, Simon & Schuster, 2001, ISBN 0-684-84944-5.
Foote, Shelby, The Civil War, A Narrative: Fredericksburg to Meridian, Random House, 1958, ISBN 0-394-49517-9.
Grant, Ulysses S., Personal Memoirs of U. S. Grant, Charles L. Webster & Company, 1885–86, ISBN 0-914427-67-9.
Kennedy, Frances H., ed., The Civil War Battlefield Guide, 2nd ed., Houghton Mifflin Co., 1998, ISBN 0-395-74012-6.
McPherson, James M., Battle Cry of Freedom: The Civil War Era (Oxford History of the United States), Oxford University Press, 1988, ISBN 0-19-503863-0.
National Park Service battle description