Defense and Siege Lines Around Vicksburg
Following the failure of the May 22 assault, Grant realized Vicksburg could not be taken by force, and decided to lay siege to the city. Slowly his army established a line of works around the beleaguered city and cut off all supplies and communications from the outside world. Commencing May 26, Union forces constructed thirteen approaches along their front aimed at different points along the Confederate defense line. Their objective was to dig up to the Confederate works, then tunnel underneath them, plant charges of black powder, and destroy the fortifications. Union troops would then be able to surge through the breaches and gain entrance to Vicksburg.
Exploding the Mine Under the Third Louisiana Redan
Harper's Weekly
Throughout the month of June, Union troops expanded their approaches slowly toward the Confederate defenses. Protected by the fire of sharpshooters and artillery, Grant's fatigue parties neared their objectives by late June. On June 25, along the Jackson Road, a mine was detonated beneath the Third Louisiana Redan, and Federal soldiers swarmed into the crater attempting to exploit the breach in the city's defenses.
Fighting in the Crater at the Third Louisiana Redan
Harper's Weekly
The struggle raged for 26 hours during which clubbed muskets and bayonets were freely used, as the Confederates fought with grim determination to deny their enemy access to Vicksburg. The troops in blue were finally driven back at the point of bayonet and the breach sealed. On July 1, a second mine was detonated but not followed by an infantry assault.
Throughout June the gallant, but weary, defenders of Vicksburg suffered from reduced rations, exposure to the elements, and constant bombardment of enemy guns. Reduced in number by sickness and battle casualties, the garrison of Vicksburg was spread dangerously thin. Soldiers and citizens alike began to despair that help would ever come. At Jackson and Canton, General Johnston gathered a relief force of over 30,000 men, which finally took up the line of march toward Vicksburg on July 1.
The threat posed by General Johnston's massive army was so great that General Grant ordered General Sherman to establish an exterior line of defense to the east of Vicksburg. Sherman constructed a line of defenses stretching from the Yazoo River in the north to the Big Black River crossings directly east of Vicksburg. General Johnston's Army of Relief reached the vicinity of the Big Black defenses on July 3rd, but by then it was too late. On the evening of July 3rd, General Pemberton called a Council of War and asked his commanders if they felt the army could break through the Union lines. After a heated discussion, the decision was made to seek terms of surrender from General Grant.
