Siege of Vicksburg (1863): Grant Wins the Mississippi River

The Siege of Vicksburg, from 18 May to 4 July 1863, was the climax of Ulysses S. Grant’s campaign to capture the Confederate fortress city of Vicksburg, Mississippi. After 47 days of siege, Confederate General John C. Pemberton surrendered his army of about 29,500 men on 4 July, the day after the Union victory at Gettysburg. The fall of Vicksburg gave the Union control of the Mississippi River and cut the Confederacy in two.

Background: the key to the Mississippi

Vicksburg stood on high bluffs on the east bank of the Mississippi, overlooking a hairpin bend in the river. Its heavy guns could fire on any vessel passing below, and it was the main link between the Confederate states east of the river and Arkansas, Louisiana and Texas to the west. Lincoln is reported to have called it the key, saying the war could never be brought to a close until that key was in the Union’s pocket.

By late 1862 the Union held most of the river: New Orleans had fallen in April 1862 and Memphis in June. Vicksburg and Port Hudson, Louisiana, were the last major Confederate strongholds. Grant’s first attempts failed. An overland advance was abandoned in December 1862 after Confederate raiders destroyed his supply base at Holly Springs, and Sherman’s attack at Chickasaw Bayou north of the city was repulsed. Through the winter of 1862-1863 Union troops tried digging canals and working through flooded bayous to bypass the guns, without success.

Grant’s spring campaign

In the spring of 1863 Grant adopted a bold plan. His army marched south along the west bank of the river in Louisiana. On the night of 16 April, Rear Admiral David Dixon Porter ran a fleet of gunboats and transports past the Vicksburg batteries, losing only one transport. Meanwhile Colonel Benjamin Grierson led a cavalry raid through the length of Mississippi, from 17 April to 2 May, distracting Pemberton.

On 30 April and 1 May Grant ferried his troops across the river to Bruinsburg, Mississippi, one of the largest amphibious operations in American history before the Second World War. Cutting loose from a fixed supply line and living partly off the land, he moved inland, winning battles at Port Gibson on 1 May, Raymond on 12 May and Jackson, the state capital, on 14 May, where he drove off Confederate forces gathering under General Joseph E. Johnston.

Turning west, Grant defeated Pemberton at Champion Hill on 16 May, the decisive battle of the campaign, and at the Big Black River Bridge on 17 May. Pemberton withdrew into the Vicksburg defences, a ring of earthworks and forts about 6 to 8 miles long.

The assaults and the siege

Hoping to take the city before its defenders recovered, Grant attacked on 19 May and again on 22 May. Both assaults failed, the second costing more than 3,000 Union casualties. Grant then settled into a formal siege, digging trenches and saps ever closer to the Confederate lines while Porter’s gunboats and Union artillery shelled the city day and night.

Union strength grew to about 75,000 to 77,000 men as reinforcements arrived, part of them facing east to block any relief attempt by Johnston, who gathered around 30,000 men but never attacked. On 25 June Union engineers exploded a mine under a Confederate earthwork, the 3rd Louisiana Redan, but troops who charged into the crater could not break through. A second mine was blown on 1 July.

Inside the city, soldiers and civilians suffered badly. Many residents dug caves into the hillsides to shelter from the shells. Rations were cut again and again, and mule meat and other animals were eaten. By the end of June much of the garrison was sick, exhausted or on short rations, and many soldiers were no longer fit to fight.

The surrender

On 3 July Pemberton asked for terms. Grant at first demanded unconditional surrender but agreed to parole the garrison, releasing the prisoners on their promise not to fight until formally exchanged, which saved him the task of shipping them north. Pemberton, a Pennsylvanian by birth, later said he chose 4 July partly in the hope of better terms on the national holiday. The Confederates marched out and stacked their arms on 4 July 1863.

Port Hudson, besieged by Union forces under Nathaniel Banks since late May, surrendered on 9 July when its commander learned of Vicksburg’s fall. In August, Lincoln wrote in a public letter that “the Father of Waters again goes unvexed to the sea.”

By the numbers

Key people

• Ulysses S. Grant: Union commander of the Army of the Tennessee, whose campaign is often studied as a masterpiece of manoeuvre.
• John C. Pemberton: Confederate commander of the Vicksburg garrison.
• David Dixon Porter: Union naval commander whose fleet ran the batteries and supported the siege.
• William T. Sherman: one of Grant’s corps commanders.
• Joseph E. Johnston: Confederate theatre commander who failed to relieve the city.

Consequences

Vicksburg’s fall, together with Gettysburg, made early July 1863 the turning point of the war. The Union now controlled the Mississippi, separating Texas, Arkansas and most of Louisiana from the rest of the Confederacy and cutting off supplies of men, cattle and goods. Grant’s reputation soared: he was given command of Union forces in the West, relieved Chattanooga in November 1863 after the Union defeat at Chickamauga, and in March 1864 was made general-in-chief of all Union armies.

Myths and facts

• Myth: Vicksburg refused to celebrate the Fourth of July for 81 years. The story is often repeated but disputed: researchers have pointed to some local Independence Day observances in the decades after the war. What is true is that the date carried painful associations in the city for a long time.
• Myth: Grant simply starved the city out. Hunger was decisive at the end, but the outcome rested on the earlier campaign of manoeuvre, in which Grant crossed the river, defeated the Confederates in the field and pinned Pemberton’s army inside its lines before Johnston could unite with it.

Legacy

Vicksburg National Military Park, established in 1899, preserves the siege lines, hundreds of monuments and the National Cemetery, where around 17,000 Union soldiers are buried, the largest number of Civil War Union dead in any national cemetery. The park also displays the ironclad gunboat USS Cairo, sunk by a mine in the nearby Yazoo River in December 1862 and raised in the 1960s. Military historians still study the campaign, and Grant’s decision to cut loose from his supply line, as an example of speed, deception and bold use of river and land forces together.

Timeline

• 1862, 29 December: Sherman’s attack at Chickasaw Bayou fails.
• 1863, 16 April: Porter’s fleet runs past the Vicksburg batteries.
• 1863, 30 April - 1 May: Grant crosses the Mississippi at Bruinsburg; battle of Port Gibson.
• 1863, 14 May: Union troops capture Jackson, Mississippi.
• 1863, 16 May: Battle of Champion Hill.
• 1863, 18 May: The siege of Vicksburg begins.
• 1863, 22 May: A general Union assault fails.
• 1863, 4 July: Pemberton surrenders Vicksburg.
• 1863, 9 July: Port Hudson surrenders.

Why it matters

The capture of Vicksburg opened the Mississippi to Union commerce and warships, split the Confederacy and destroyed a whole Confederate army. Coming a day after the Battle of Gettysburg, it marked the moment when the war turned decisively against the South and made Grant the general who would lead the Union to victory.