The Siege of Vicksburg, 1863

May 25–July 4, 1863

General Ulysses S. Grant's successful siege of the City of Vicksburg, Mississippi in 1863 divided the Confederacy and secured Union control of the Mississippi River.

Portrait of John C. Pemberton

On July 4, 1863, Lieutenant General John C. Pemberton surrendered the city of Vicksburg and the Confederate garrison defending it to Major General Ulysses S. Grant. [Wikimedia Commons]

Prelude to the Siege

By late 1861, President Abraham Lincoln was pressuring Union commanders in the west to invade the South. On January 30, 1862, the Western Theater commander, General Henry Halleck, reluctantly approved Brigadier General Ulysses S. Grant’s request to attack Fort Henry on the Tennessee River. Eager to move, Grant left Cairo, Illinois on February 2, with 15,000 soldiers, plus a flotilla of seven gunboats, commanded by United States Navy Flag Officer Andrew Hull Foote. On February 6, Confederate Brigadier General Lloyd Tilghman surrendered Fort Henry after a seventy-five-minute bombardment by Foote’s gunboats. Following the surrender of Fort Henry, Grant turned his attention toward investing Fort Donelson, located just twelve miles to the east of Fort Henry on the Cumberland River. After a failed breakout on February 15, the Confederate commander of Fort Donelson, General Simon B. Buckner, surrendered Fort Donelson to Grant the next day.

With two of the three main rivers connecting the North and South under Union control, the Federals turned their attention to the Mississippi River. If the Union could gain control of the Mississippi, the Confederacy would lose easy access to supplies from the Gulf of Mexico and territories in the American West. Admiral David Farragut captured the port city of New Orleans on May 18, 1862, closing down Confederate access to the Gulf. In June, the Union tightened its grip on the Mississippi, when Federal forces captured the river city of Memphis, Tennessee. Nevertheless, the South still controlled traffic on much of the river because of its strong fortifications at Vicksburg, Mississippi.

Vicksburg Geography

Vicksburg sits on a high bluff on the eastern side of the Mississippi River, south of the mouth of the Yazoo River.  Known as “The Gibraltar of the Confederacy,” the city seemed to be impregnable. The height of the cliff on which it sat protected it from amphibious assaults. To the north, nearly impenetrable swamps and bayous protected Vicksburg. To the east, a ring of forts, mounting 172 guns, shielded the city from overland assaults. The land on the Louisiana side of the river, opposite Vicksburg, was rough, etched with poor roads and many streams.

Grant Bypasses Vicksburg

In July 1862, President Abraham Lincoln summoned Major General Henry W. Halleck to Washington to serve as chief of all Union armies. Halleck’s departure left Major General Ulysses S. Grant in charge of operations in the Western Theater.

In December 1862, Grant launched the first of several unsuccessful attempts to capture Vicksburg. When spring arrived, he tried a new, more complicated plan. On March 29, 1863, Grant put part of his army to work constructing bridges, draining bayous, and building a road past Vicksburg on the west side of the Mississippi. By May 1, his army had recrossed the river at Bruinsburg, Mississippi, and established a base of operations at Port Gibson.

Grant Occupies Jackson, Mississippi

Before assaulting Vicksburg, Grant turned his attention to an army that General Joseph Johnston was assembling in Jackson, Mississippi, forty miles to the east of Vicksburg. By May 14, 1863, Union soldiers overpowered Johnston’s rearguard as he evacuated Jackson in the face of Grant’s larger army. After ordering the destruction of anything in the city that could support the Southern war effort, Grant marched his army back toward Vicksburg.

Pemberton Fails to Halt Grant

On May 16, 1863, Lieutenant General John C. Pemberton, the Confederate commander of the Army of Mississippi, unsuccessfully tried to halt Grant’s advance on Vicksburg by attacking the Union army at the Battle of Champion Hill, twenty miles east of the city. The next day, the Confederates made another futile stand at the Battle of Big Black River Bridge. With no other options, Pemberton ordered his men to burn the bridges spanning the river, gather everything edible in their path, and retreat to the safety of Vicksburg.

Vicksburg Under Siege

Grant made two attempts to storm Vicksburg on May 19, and on May 22. Neither assault was successful, costing the Federals 639 killed, 3,277 wounded and 155 missing men. Rather than suffer further Union casualties, Grant besieged Vicksburg. On May 25, the Army of the Tennessee started to dig in, creating entrenchments around the city.

A week earlier, on May 19, William T. Sherman’s cavalry had forced the Confederates to evacuate their gun battery at Hayne’s Bluff, enabling Grant to establish a direct supply line on the Mississippi River to feed, arm, and reinforce his army.  As Grant’s forces swelled to nearly 75,000 Yankees, Pemberton’s only hope for escape was the possibility of General Johnston raising an army and marching against Grant from the east. Johnston did not share the belief held by others about Vicksburg’s military importance, so help never came.

With no supplies coming into the city, citizens and soldiers alike suffered from a lack of food. Gradually, the poor diet led to the onset of diseases, including scurvy, malaria, dysentery, and diarrhea. To add to the misery, Union artillery batteries and Farragut’s gunboats on the river lobbed thousands of shells into the city, forcing citizens to dig and inhabit over 500 caves for shelter.

Pemberton Surrenders

On July 3, 1863, Pemberton asked Grant for terms of surrender. Initially, Grant proposed an unconditional surrender, as he had done at Fort Donelson. Upon further reflection though, Grant decided that he did not want the burden of nearly 30,000 starving prisoners in poor health. Instead, he offered to parole all the Rebels, hoping that they would not take up arms against the Union again. On July 4, 1863, the opposing generals reached an accord and Pemberton surrendered the city and his garrison. The Confederate government later challenged the terms of parole on technical issues and some prisoners Grant paroled fought against the North at Chattanooga and during Sherman’s Atlanta Campaign.

Aftermath of the Siege


The surrender of Vicksburg was a significant turning point in the American Civil War. Before the campaign began, President Abraham Lincoln stated, “Vicksburg is the key. The war can never be brought to a close until the key is in our pocket.” Confederate President Jefferson Davis said, “Vicksburg is the nail head that holds the South’s two halves together.” Both were correct. Vicksburg’s fall gave the Union complete control of the Mississippi River, reestablishing trade through the Gulf of Mexico. It also severed the Confederacy’s connections with territories in the American West, denying the South essential agricultural supplies.

Darkest Two Days in Confederate Military History

Combined with Major General George G. Meade’s victory at Gettysburg (July 3), Confederate General Braxton Bragg’s retreat from Middle Tennessee at the conclusion of Major General William S. Rosecrans’ highly successful Tullahoma Campaign (July 3), and Major General Benjamin Prentiss’ triumph over Confederate troops in Arkansas at the Battle of Helena (July 4), Grant’s victory at Vicksburg completed the darkest two days in Confederate military history.

Grant’s success at Vicksburg also restored his reputation, which had suffered after the surprise Confederate attack at Shiloh. The renewed confidence in Grant would have a decisive impact on later events in the Eastern Theater and on the final chapters of the war.