The Union campaign against Vicksburg, in its entirety, would be the longest of the Civil War. Its first phase began with a naval bombardment on May 18, 1862, which failed due to the fierce resistance of the Confederate batteries guarding the city. That winter, Union forces made an unsuccessful attempt to take Vicksburg by land from the north. In the spring of 1863, General Ulysses S. Grant conceived a bold new plan: By marching his Army of the Tennessee down the Mississippi River on its western bank, he could cross the river and approach Vicksburg from the south, giving his troops a more favorable position. 

On March 29, some 40,000 of Grant’s men began marching from Milliken’s Bend to Hard Times, Louisiana. Meanwhile, a Union flotilla commanded by Rear Admiral David Porter ran past the Vicksburg defenses in mid-April, managing to slip by despite being hit hard by Confederate batteries and rendezvous with Grant at Hard Times.

After a thwarted initial crossing at Grand Gulf on April 29, Grant continued southward and was able to make the crossing on April 30-May 1 at Bruinsburg, Mississippi. The infantrymen of the 24th and 46th Indiana Regiments were the first troops to land, followed by the remainder of the XIII Union Army Corps and portions of the XVII Corps (17,000 men in all). The landing would stand as the largest amphibious operation in American military history until the Allied invasion of Normandy during World War II.

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Grant began quickly moving his army northeast, taking Port Gibson on May 2, Grand Gulf on May 3 and Jackson, the state capital, on May 14. These victories would prevent the small Confederate force led by General Joseph Johnston from linking up with their comrades at Vicksburg, commanded by General John C. Pemberton. On May 16, the most decisive military engagement of the campaign took place at Champion Hill, in which the Federal army forced Pemberton’s army to withdraw to Vicksburg and prepare to defend the city at all costs. After initial assaults on the city were rebuffed, Grant settled his army in for a long siege by May 29. His army built miles of trenches and slowly sealed off the city, enclosing Pemberton’s 29,000 troops and cutting them off from all supplies and communication.

Conditions deteriorated quickly for Vicksburg’s military and civilian population under siege. Running out of vital ammunition and supplies, they suffered from exposure to the Mississippi’s hot summer climate. Soldiers’ daily rations continued to shrink: At one point during the siege, they consisted of a quarter pound of bacon and of flour, an eighth of a pound of sugar, 1/12 of a quart of peas and 1/50 of a gallon of molasses. Civilians were forced to make do with similar portions. To escape the constant Union bombardment, many of Vicksburg’s residents burrowed into tunnels dug into the hills.

Confederate attempts to aid Vicksburg from both east and west were unsuccessful. Johnston, who had wanted to abandon the city before the siege rather than risk losing Pemberton’s army, assembled a relief force at Jackson and Canton. In mid-June, he had 28,000 men; combined with Pemberton’s army, they would have enjoyed a brief numerical advantage over Grant (though the Union general had reinforcements on the way.) But Johnston seemed reluctant to act, and by the time the relief force began its march towards Vicksburg on July 1, it was too late. That day, Pemberton polled his generals on the viability of fighting their way out of Vicksburg; like him, they all considered it an impossibility. On the afternoon of July 3, white flags appeared on the city’s defensive works, as Pemberton rode out to meet with Grant and discuss terms of surrender.

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Unable to reach an agreement, the two generals separated, with Grant promising to send his terms by 10 pm that night. That meant that the actual surrender could not occur before the next day: July 4. The date was most likely accidental, even though Pemberton later argued that he chose to delay because he thought he could get better terms on such an important U.S. holiday. Instead of unconditional surrender, Grant offered parole to the defenders of Vicksburg, and Pemberton and his generals decided this was the best they could hope for. At 10 am on July 4, white flags appeared again, as Pemberton’s army marched out from their defenses and laid down their arms. Union forces then marched in and took control of the city, ending the siege of Vicksburg.

Vicksburg’s fall divided the Confederacy in half, leaving the Union in firm control of the Mississippi River. With the campaign, U.S. Grant proved his military mettle and won the unwavering confidence of his commander in chief, Lincoln, who would soon make him commander in chief of all Union armies. The loss of Vicksburg, along with the entirety of Pemberton’s army, decimated Southern morale and divided its leadership to the highest levels, as Confederate President Jefferson Davis was disgusted with Johnston’s reluctance to come to Pemberton’s aid. Together with the Union defeat of Robert E. Lee’s army at Gettysburg the previous day, the fall of Vicksburg would turn the tide of the Civil War.

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After the surrender, Vicksburg’s proud citizens endured enemy occupation while they tried to rebuild their once-robust town. For years, a story persisted that anti-Union feelings remained so strong in Vicksburg that its residents did not celebrate the 4th of July until the mid-20th century. While it’s certainly a compelling idea, historians have recently questioned this version of events, based on several factors. For one thing, Federal troops occupied Vicksburg well into Reconstruction—many Union soldiers would even marry local women—and surely these troops celebrated on the 4th, no doubt joined by some Vicksburgians. And even after Federal troops left, anecdotes from generations of city residents indicate 4th of July celebrations took place. 

It is not known whether Vicksburg city officials sanctioned commemoration of the 4th, but private citizens, and even businesses, may still have observed the holiday without such official sanction. In any case, Southern celebrations of July 4th were generally (for many years both before and after the Civil War) more likely to be family picnics rather than formal city or county activities such as parades or other public events.