Battle of Jackson , Mississippi The Battle of Jackson , fought on May 14 , 1863 , in Jackson , Mississippi , was part of the Vicksburg Campaign in the American Civil War . Union commander Maj . Gen . Ulysses S . Grant and the Army of the Tennessee defeated Confederate General Joseph E . Johnston , seizing the city , cutting supply lines , and opening the path to the west and the Siege of Vicksburg . Background . On May 9 , Gen . Johnston received a dispatch from the Confederate Secretary of War directing him to " proceed at once to Mississippi and take chief command of the forces in the field . " As he arrived in Jackson on May 13 , from Middle Tennessee , he learned that two army corps from the Union Army of the Tennessee — the XV , under Maj . Gen . William T . Sherman , and the XVII , under Maj . Gen . James B . McPherson — were advancing on Jackson , intending to cut the city and the railroads off from Vicksburg , Mississippi which was a major port on the Mississippi River . These corps , under the overall command of Grant , had crossed the Mississippi River south of Vicksburg and driven northeast toward Jackson . The railroad connections were to be cut to isolate the Vicksburg garrison . And if the Confederate troops in Jackson were defeated , they would be unable to threaten Grant ' s flank or rear during his eventual assault on Vicksburg . Battle . Johnston consulted with the local commander , Brig . Gen . John Gregg , and learned that only about 6 , 000 troops were available to defend the town . Johnston ordered the evacuation of Jackson , but Gregg was to defend Jackson until the evacuation was completed . By 10 a . m . , both Union army corps were near Jackson and had engaged the enemy . Rain , Confederate resistance , and poor defenses prevented heavy fighting until around 11 a . m . , when Union forces attacked in numbers and slowly but surely pushed the enemy back . In mid - afternoon , Johnston informed Gregg that the evacuation was complete and that he should disengage and follow . Aftermath . Soon after , Union troops entered Jackson and had a celebration in the Bowman House , hosted by Grant , who had been traveling with Sherman ' s corps . They then burned part of the town and cut the railroad connections with Vicksburg . Johnston ' s evacuation of Jackson was premature because he could , by late on May 14 , have had 11 , 000 troops at his disposal and by the morning of May 15 , another 4 , 000 . The fall of the former Mississippi state capital was a blow to Confederate morale . General Sherman appointed Brig . Gen . Joseph A . Mower to the position of military governor of Jackson and ordered him to destroy all facilities that could benefit the war effort . With the discovery of a large supply of rum , it was impossible for Mower ' s Brigade to keep order among the mass of soldiers and camp followers , and many acts of pillage took place . Grant left Jackson on the afternoon of May 15 and proceeded to Clinton , Mississippi . On the morning of May 16 he sent orders for Sherman to move out of Jackson as soon as the destruction was complete . Sherman marched almost immediately , clearing the city by 10 a . m . . By nightfall on May 16 , Sherman ' s corps reached Bolton , Mississippi , and the Confederacy had reoccupied what remained of Jackson . Jackson had been destroyed as a transportation center and the war industries were crushed . But more importantly the Confederate concentration of men and materials aimed at saving Vicksburg were scattered . Sherman would later lead an expedition against Jackson following the fall of Vicksburg to clear Johnston ' s relief force from the area .