Home / American Civil War / The Siege of Vicksburg: A Crucial Win for the Union Army
The Siege of Vicksburg: A Crucial Win for the Union Army
By MSG Garrett D. Roberson Jr.

A Strategic Win for the North

The American Civil War saw countless numbers of skirmishes, engagements, bombardments, and battles throughout its duration; however, some battles posed greater significance than others. Perhaps the most famed battle of the Civil War was Gettysburg, where the Union Army decimated the Confederate force over the first three days in July of 1863 (Reardon & Vossler, 2013). While the Union's win at Gettysburg was significant to the North's war effort, General Ulysses S. Grant won the Vicksburg Campaign during the same timeframe. The Battle of Gettysburg vastly overshadowed the Vicksburg Campaign, even though the Union Army's victory at Vicksburg played a critical role in turning the tide of the Civil War in the North's favor. Vicksburg served as an even more crucial victory for the North than Gettysburg because the Union Army cut the South's supply lines from the Mississippi River, forced the surrender of 29,000 Confederates, and ultimately broke the fighting spirit of the South.

The Value of the Mississippi River During the War

By October 1862, the Union Army possessed control of the Mississippi River from its source down to Vicksburg, Mississippi, and from the Gulf of Mexico and upstream to Port Hudson, Louisiana (Ambrose, 1992). Because of the Union's vast control over much of the river, the city of Vicksburg served as a key strategic location for the Confederate Army. It permitted the Confederacy access to a portion of the Mississippi River, which acted as a primary supply route that granted access to cattle from Texas, salt from Arkansas, and steel from Missouri – all of which were vital resources to the South's ability to sustain a fighting force (Wheeler, 1978). The South's control of the city also enabled free and unbroken lines of communication from western Confederate forces to their units fighting in the East. Ambrose (1992) contends that Vicksburg sat atop a 200-foot bluff, and the Confederates fortified the upper and lower portions of the city to ensure its defense from amphibious assaults while the natural characteristics of the river's local surroundings made attacks from other avenues nearly impossible. The strategic importance of Vicksburg was clear to both the North and the South, and even President Abraham Lincoln told his officers that it was the key to winning the war (Wheeler, 1978). The Commander of the Army of Virginia, General Robert E. Lee, also understood this point and appointed Lieutenant General John C. Pemberton as the commander of the Department of Mississippi and East Louisiana (Winschel & Bearss, 1999). General Pemberton's Union counterpart, General Grant, had tried various tactics to root out the Confederate bastion but failed in previous attempts.

Grant's campaign comprised a series of rapid maneuvers and battles throughout Louisiana and Mississippi; however, the city of Vicksburg had always been the primary target. In his hasty maneuvers, Grant finally took key ground at Raymond, Port Gibson, and Jackson, Mississippi (Woodworth & Grear, 2013). During his stint in Jackson, Mississippi, General Grant ordered the destruction of anything of military value to ensure he did not have to leave troops in permanent occupation of the capital city. After neutralizing the capital, Grant lured Pemberton out of Vicksburg, and the two armies finally met just outside Vicksburg at Champion Hill. The action during the Battle of Champion Hill overwhelmed the Confederate Army and pushed Pemberton back toward Vicksburg. A day later, on May 17th, 1863, Grant again encountered Pemberton's Army, this time at the Battle of the Big Black River (Ambrose, 1992). With another significant loss, Pemberton retreated into the city with no way of escape and without allied support.

Forcing the Enemy’s Hand

At the climax of the Vicksburg Campaign, "Pemberton’s total strength on the field was about 23,000, opposed to Grant’s 32,000" (Ambrose, 1992, p. 26). After his win at the Battle of the Big Black River and encircling Pemberton's Army inside the city of Vicksburg, Grant turned to siege tactics. Unlike skirmishes and battles, sieges are a much longer and more enduring ordeal. The siege of Vicksburg is no different from this paradigm and lasted 47 days. Furthermore, Grant's seizure of Port Gibson enabled the Union Navy to access the waters outside Vicksburg, and he ordered the Union's Navy to shell Vicksburg from the Mississippi River throughout the 47-day siege. Pemberton's trapped Army of roughly 30,000 men, alongside some 5,000 civilians, lived through a demoralizing and dramatic shift in suitable living conditions.

After the siege began, citizens and Soldiers could not leave the city, and Pemberton's forces grew ill and malnourished over time. Grant planned to force starvation on the troops inside Vicksburg, ultimately driving Pemberton to surrender (Ambrose, 1992). Miniscule rations of food and water did not fuel the Confederate's fighting force; however, these conditions fed disease throughout the city instead. Winschel and Bearss (1999) assert that diseases such as dysentery, diarrhea, malaria, and other fevers spread quickly and killed more troops than Soldiers in blue. The daily bombings from the Union Navy also added to the unhospitable living conditions. The explosions destroyed countless houses, forcing many of the city's inhabitants to seek shelter in makeshift caves dug into the city's hills to escape the North's cannon fire (Winschel & Bearss, 1999). Grant's plan eventually worked, and Pemberton sent a courier under a white flag to Grant's headquarters for terms of surrender.

Crippling the South’s Resolve

In his typical fashion, Grant responded to Pemberton's courier and said he would take nothing less than unconditional surrender (Winschel & Bearss, 1999). Grant understood just how diminished Pemberton's Army was by the end of the siege, and he felt that Pemberton would be in no condition to haggle with terms of surrender. Winschel & Bearss (1999) indicate that the conditions and hardships created by Grant's siege affected the Confederate Army both physically and mentally. Daily bombings, disease, starvation, and no sign of reprieve took their toll on the Gray Soldiers, resulting in the Confederate's resolve slipping away. The Soldiers under Pemberton's command wrote a letter titled "Appeal for Help" and effectively stated that General Pemberton must either feed his Army or surrender them, lest they resort to dishonoring the South by deserting the Army (Winschel & Bearss, 1999).

In disbelief of Grant's terms, General Pemberton decided to personally meet with General Grant to secure a better option than unconditional surrender. During their meeting, Pemberton asked Grant what terms he would offer, and Grant responded that he would accept nothing other than the unconditional surrender of the city and garrison (Ambrose, 1992). Unable to strike an agreement, Grant suggested that subordinates from his staff engage with officers from Pemberton's staff to work out agreeable terms for both sides (Ambrose, 1992). After a short period, staff officers from both sides created terms acceptable to both Pemberton and Grant. Those terms were Vicksburg's complete and total surrender in exchange for the parole of more than 29,000 of Pemberton's troops (Ambrose, 1992). Starved, physically and mentally exhausted, many Confederate veterans would accept their parole and cease fighting altogether.

The Vicksburg Campaign successfully concluded on July 4th, 1863, and the victory secured one of the North's most important wins in the Civil War (Wheeler, 1978). The Union's win at Vicksburg landed a heavy blow to the Confederacy's determination; however, the spirit of the South's civilians took a massive hit too. Winschel and Bearss (1999) contend that General Grant caused more than 9,000 Confederate casualties, captured 172 artillery pieces and over 50,000 rifles, and forced the surrender of over 29,000 Confederate Soldiers before the end of the Vicksburg Campaign. These personnel and equipment losses were invaluable to the Southern Army and were not merely replaceable. Winschel and Bearss (1999) framed the South's view of the loss of Vicksburg as the Confederacy's death knell. The South seemed to understand this all too well as the war ended less than two years later when General Robert E. Lee surrendered at Appomattox Court House (National Park Service, 2018).

Aftermath and Affects

If General Grant had been unsuccessful in his Vicksburg Campaign, the North could have easily lost the Civil War. On the contrary, Grant's success at Vicksburg spurred General Lee to move the Army of Northern Virginia across Maryland and into Pennsylvania in an attempt to draw Grant out from Mississippi (Winschel & Bearss, 1999). This move from Lee's Army placed the Confederacy in Gettysburg, Pennsylvania. Unfortunately for the South, Grant did not leave Mississippi to pursue Lee, and Lee's miscalculation of Grant's response to the Confederate Army moving northward cost him dearly. The South's casualty toll from the famed Battle of Gettysburg sat at over 20,000 casualties – nearly one-third of Lee's force (Reardon & Vossler, 2013).

Perhaps the most significant loss to the South came not from casualties from battle but from choking off supply lines and splitting the Confederate forces after the North assumed complete control of the Mississippi River. The Confederacy's President, Jefferson Davis, once said, "Vicksburg is the nailhead that holds the South’s two halves together." (Davis, n.d., as cited in the National Park Service, 2019). With the entire length of the Mississippi River now under the Union's control, the Confederacy lost access to Louisiana, Texas, and Arkansas. This loss of access was especially harmful because Confederate suppliers frequently traveled via the Texas-Mexico border, and the now impassable river also eliminated any chance of French assistance across the border (American Battlefield Trust, 2021).

The aftermath of Grant's Vicksburg Campaign presented a bleak forecast for the South's success. Grant's victory also effectively shifted the Union's posture toward winning the war. Vicksburg marked a significant milestone for the Union and served as an important personal achievement for General Grant. His win at Vicksburg enhanced his prestige and reputation as a field commander and eventually led to his selection as the Union Armies' General-in-Chief (American Battlefield Trust, 2021). As General-in-Chief, Grant pursued Lee up until Lee's surrender at Appomattox Court House (National Park Service, 2018).


Vicksburg served as an even more crucial victory for the North than Gettysburg because the Union Army cut the South's supply lines from the Mississippi River, forced the surrender of 29,000 Confederates, and ultimately broke the fighting spirit of the South. As history has shown, it turned out that both President Lincoln's and President Davis's views on Vicksburg were painfully accurate. The North's seizure of the entire Mississippi River and the staggering number of forfeited Confederate fighters and equipment completely sapped the South's fighting spirit. Neither the North nor the South could afford to lose the key ground attached to the Mississippi River, and Vicksburg clearly served as the turning point in the war for both sides. If Gettysburg was the nail in the Confederacy's proverbial coffin, then Vicksburg served as the lid to that coffin. The loss of Vicksburg signified the beginning of the end for the Southern cause and proved to be an essential victory for the North.

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Show Notes
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© 2024 Garrett D. Roberson Jr.

Written by Garrett Roberson Jr.

About the author:
MSG Garrett D. Roberson Jr. is a current student of the U.S. Army’s Sergeants Major Academy at Ft. Bliss, Texas. He has served in the U.S. Army since age 17 and has over 21 years of service. He has served in multiple leadership positions, ranging from squad leader, section chief, platoon sergeant, chief instructor, and first sergeant.MSG Roberson’s next assignment will be as an operations sergeant major at the division level.

* Views expressed by contributors are their own and do not necessarily represent those of MilitaryHistoryOnline.com.

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