The siege of Vicksburg (May 18 – July 4, 1863) was the final major military action in the Vicksburg campaign of the American Civil War. In a series of maneuvers, Union major general Ulysses S. Grant and his Army of the Tennessee crossed the Mississippi River and drove the Confederate Army of Mississippi, led by Lieutenant General John C. Pemberton, into the defensive lines surrounding the fortress city of Vicksburg, Mississippi, leading to the successful siege and Confederate surrender.
Vicksburg was the last major Confederate stronghold on the Mississippi River; therefore, capturing it completed the second part of the Northern strategy, the Anaconda Plan. When two major assaults against the Confederate fortifications, on May 19 and 22, were repulsed with heavy casualties, Grant decided to besiege the city beginning on May 25. After holding out for more than 40 days, with their supplies nearly gone, the garrison surrendered on July 4. The Vicksburg campaign's successful ending significantly degraded the Confederacy's ability to maintain its war effort. This action, combined with a siege that led to the surrender of the downriver Port Hudson to Major General Nathaniel P. Banks on July 9, yielded command of the Mississippi River to the Union forces, which held it for the rest of the conflict.
The Confederate surrender on July 4, 1863 is sometimes considered, combined with General Robert E. Lee's defeat at Gettysburg by Major General George Meade the previous day, the war's turning point. It cut off the Trans-Mississippi Department (containing the states of Arkansas, Texas and part of Louisiana) from the rest of the Confederate States, effectively splitting the Confederacy in two for the rest of the war. Lincoln called Vicksburg "the key to the war."
Background
Military situation
After crossing the Mississippi River south of Vicksburg at Bruinsburg and driving northeast, Grant won battles at Port Gibson and Raymond and captured Jackson, the Mississippi state capital, on May 14, 1863, forcing Pemberton to withdraw westward. Attempts to stop the Union advance at Champion Hill and Big Black River Bridge were unsuccessful. Pemberton knew that the corps under Maj. Gen. William T. Sherman was preparing to flank him from the north, and so had no choice but to withdraw or be outflanked. Pemberton burned the bridges over the Big Black River and devastated the countryside as he retreated to the heavily defended city of Vicksburg.
The Confederates evacuated Haynes' Bluff, which was subsequently occupied by Sherman's cavalry on May 19, and Union steamboats no longer had to run the guns of Vicksburg, now being able to dock by the dozens up the Yazoo River. Grant could now receive supplies more directly than by the previous route, which ran through Louisiana, over the river crossing at Grand Gulf and Bruinsburg, then back up north.
Over half of Pemberton's army had been lost in the two preceding battles and many in Vicksburg expected General Joseph E. Johnston, in command of the Confederate Department of the West, to relieve the city—which he never did. Large numbers of Union troops were on the march to invest the city. They repaired the bridges over the Big Black River and crossed on May 18. Johnston urged his general, Pemberton, to abandon the city in order to save his troops—a demand Pemberton refused. Pemberton, a Northerner by birth, was probably influenced by his fear of public condemnation if he abandoned Vicksburg.
Pemberton, trying to please Jefferson Davis, who insisted that Vicksburg and Port Hudson must be held, and to please Johnston, who thought both places worthless militarily, had been caught in the middle, a victim of a convoluted command system and his own indecisiveness. Too dispirited to think clearly, he chose to back his bedraggled army into Vicksburg rather than evacuate the city and head north where he might have escaped to campaign again. When he chose to take his army into Vicksburg, Pemberton sealed the fate of his troops and the city he had been determined to defend.
— Vicksburg, Michael B. Ballard.
Fortifications
As the Union forces approached Vicksburg, Pemberton could put only 18,000 troops in his lines. Grant had over 35,000, with more on the way. However, Pemberton had the advantage of terrain and fortifications that made his defense nearly impregnable. The defensive line around Vicksburg ran for approximately six and a half miles (10 km), based on terrain of varying elevations that included hills and knobs with steep slopes which would require an attacker to ascend them under fire. The perimeter included many gun pits, forts, trenches, redoubts, and lunettes. The major fortifications of the line included: Fort Hill, on a high bluff north of the city; the Stockade Redan, dominating the approach to the city on Graveyard Road from the northeast; the 3rd Louisiana Redan; the Great Redoubt; the Railroad Redoubt, protecting the gap for the railroad line entering the city; the Square Fort (Fort Garrott); a salient along the Hall's Ferry Road; and the South Fort.
Opposing forces
Union
Maj. Gen. Ulysses S. Grant's Union Army of the Tennessee brought five corps to the siege:
Confederate
Lt. Gen. John C. Pemberton's Confederate Army of Mississippi inside the Vicksburg line consisted of four divisions, under Maj. Gens.:
Siege
Assaults
Grant wanted to overwhelm the Confederates before they could fully organize their defenses and ordered an assault against the Stockade Redan for May 19. Troops from Sherman's corps had a difficult time approaching the position under rifle and artillery fire from the 36th Mississippi Infantry, Brig. Gen. Louis Hébert's brigade. They had to negotiate a steep ravine protected by abatis and cross a 6-foot-deep (1.8 m), 8-foot-wide (2.4 m) ditch before attacking the 17-foot-high (5.2 m) walls of the redan. This first attempt was easily repulsed. Grant ordered an artillery bombardment to soften the defenses and at about 2 pm, Sherman's division under Maj. Gen. Francis P. Blair tried again, but only a small number of men were able to advance even as far as the ditch below the redan. The assault collapsed in an exchange of rifle fire and hand grenades lobbing back and forth.
The failed Union assaults of May 19 shattered the confidence built from recent victories in Mississippi, costing 157 killed, 777 wounded, and eight missing, while Confederate losses were only eight killed and 62 wounded—proof that the supposedly demoralized defenders had regained their fighting edge.
Grant planned another assault for May 22, but this time with greater care; his troops would first reconnoiter thoroughly and soften up the defenses with artillery and naval gunfire. The lead units were supplied with ladders to ascend the fortification walls. Grant did not want a long siege, and this attack was to be by the entire army across a wide front.
Despite their bloody repulse on May 19, Union troops were in high spirits, now well-fed with provisions they had foraged. On seeing Grant pass by, a soldier commented, "Hardtack". Soon all Union troops in the vicinity were yelling, "Hardtack! Hardtack!" The Union served hardtack, beans, and coffee the night of May 21. Everyone expected that Vicksburg would fall the next day.
Union forces bombarded the city all night, from 220 artillery pieces and with naval gunfire from Rear Adm. David D. Porter's fleet in the river. While causing little property damage, they damaged Confederate civilian morale. On the morning of May 22, the defenders were bombarded again for four hours before the Union attacked once more along a 3-mile (5 km) front at 10 am.
Sherman attacked once again down the Graveyard Road, with 150 volunteers (known as the forlorn hope detachment) leading the way with ladders and planks, followed by the divisions of Blair and Brig. Gen. James M. Tuttle, arranged in a long column of regiments. They hoped to achieve a breakthrough by concentrating their mass on a narrow front. They were driven back in the face of heavy rifle fire. Blair's brigades under Cols. Giles A. Smith and T. Kilby Smith made it as far as a ridge 100 yards from Green's Redan, the southern edge of the Stockade Redan, from where they poured heavy fire into the Confederate position, but to no avail. Tuttle's division, waiting its turn to advance, did not have an opportunity to move forward. On Sherman's far right, the division of Brig. Gen. Frederick Steele spent the morning attempting to get into position through a ravine of the Mint Spring Bayou.
McPherson's corps was assigned to attack the center along Jackson Road. On their right flank, the brigade of Brig. Gen. Thomas E. G. Ransom advanced to within 100 yards of the Confederate line, but halted to avoid dangerous flanking fire from Green's Redan. On McPherson's left flank, the division of Maj. Gen. John A. Logan was assigned to assault the 3rd Louisiana Redan and the Great Redoubt. The brigade of Brig. Gen. John E. Smith made it as far as the slope of the redan, but huddled there, dodging grenades until dark, when they were recalled. Brig. Gen. John D. Stevenson's brigade advanced in two columns against the redoubt, but their attack also failed when they found their ladders were too short to scale the fortification. Brig. Gen. Isaac F. Quinby's division advanced a few hundred yards, but halted for hours while its generals engaged in confused discussions.
On the Union left, McClernand's corps moved along the Baldwin Ferry Road and astride the Southern Railroad of Mississippi. The division of Brig. Gen. Eugene A. Carr was assigned to capture the Railroad Redoubt and the 2nd Texas Lunette; the division of Brig. Gen. Peter J. Osterhaus was assigned the Square Fort. Carr's men achieved a small breakthrough at the 2nd Texas Lunette and requested reinforcements.
By 11 am, it was clear that a breakthrough was not forthcoming and that the advances by Sherman and McPherson were failures. Just then, Grant received a message from McClernand, which stated that he was heavily engaged, the Confederates were being reinforced, and he requested a diversion on his right from McPherson's corps. Grant initially refused the request, telling McClernand to use his own reserve forces for assistance; Grant was mistakenly under the impression that McClernand had been lightly engaged and McPherson heavily, although the reverse was true. McClernand followed up with a message that was partially misleading, implying that he had captured two forts—"The Stars and Stripes are flying over them."—and that another push along the line would achieve victory for the Union Army. In fact, more than a dozen members of the 22nd Iowa Infantry Regiment had secured a tenuous foothold in a portion of the fortification known as the Railroad Redoubt, and forced Confederate defenders back from that point, though the Iowans could not advance further. Although Grant once again demurred, he showed the dispatch to Sherman, who ordered his own corps to advance again. Grant, reconsidering, then ordered McPherson to send Quinby's division to aid McClernand.
As our line of battle started and before our yell had died upon the air the confederate fortifications in our front were completely crowded with the enemy, who with an answering cry of defiance, poured into our ranks, one continuous fire of musketry, and the forts and batteries in our front and both sides, were pouring in to our line, an unceasing fire of shot and shell, with fearful results, as this storm of fire sent us, intermixed with the bursting shells and that devilish rebel yell, I could compare to nothing but one of Dante's pictures of Hell, a something too fearful to describe.
— Daniel A. Ramsdell, Ransom's Brigade
Sherman ordered two more assaults. At 2:15 pm, Giles Smith and Ransom moved out and were repulsed immediately. At 3 pm, Tuttle's division suffered so many casualties in their aborted advance that Sherman told Tuttle, "This is murder; order those troops back." By this time, Steele's division had finally maneuvered into position on Sherman's right, and at 4 pm, Steele gave the order to charge against the 26th Louisiana Redoubt. They had no more success than any of Sherman's other assaults.
In McPherson's sector, Logan's division made another thrust down the Jackson Road at about 2 pm, but met with heavy losses and the attack was called off. McClernand attacked again, reinforced by Quinby's division, but with no success. Union casualties for the day totalled 502 killed, 2,550 wounded, and 147 missing, about evenly divided across the three corps. Confederate casualties were not reported directly, but are estimated to have been under 500. Grant blamed McClernand's misleading dispatches for part of the poor results of the day, storing up another grievance against the political general who had caused him so many aggravations during the campaign.
Siege operations
Shelby Foote wrote that Grant "did not regret having made the assaults; he only regretted that they had failed." Grant reluctantly settled into a siege. On May 25, Lt. Col. John A. Rawlins issued Special Orders No. 140 for Grant:
Corps Commanders will immediately commence the work of reducing the enemy by regular approaches. It is desirable that no more loss of life shall be sustained in the reduction of Vicksburg, and the capture of the Garrison. Every advantage will be taken of the natural inequalities of the ground to gain positions from which to start mines, trenches, or advance batteries. ...