Sherman also senses the rebels are not serious about fighting. So, despite facing water a foot deep across his path, despite facing a continuing downpour, and despite not being certain about the condition of his soldier’s powder, Sherman orders his men forward at the bayonet, looking for weak points. At about 10AM they cross the Plum Creek and the Lynch Creek Bridge and quickly drive the Confederates back into their fortifications. Meanwhile, to the North, on the Union right flank, General McPherson has pushed two divisions, commanded by Generals Logan and M.M. Crocker, forward to pin down the rebel troops.
By noon Crocker and Logan’s men have driven the Confederates back into their fortifications, and McPherson calls a halt to feel out the rebel lines. At the same time, to the South and West of Jackson, Sherman’s Corp is tapping the Confederate lines at the bridge over Plum Creek, and sends General Tuttles’s division Eastward to outflank the rebel line. There, just after 2pm, General Tuttle finds the fortifications empty. The Confederate General Gregg has received orders to withdraw North along the Central Mississippi Railroad and the Canton Road.
The “Battle of Jackson” has cost Grant’s army 42 dead, 25 wounded and 7 missing. Gregg lost about 845 dead, wounded and captured, affirming Johnston’s decision not to stand and fight with a mix of militia and regulars against a far stronger Union force. Sherman’s men enter Jackson at about 4pm, and almost immediately Grant begins issuing orders to abandon the newly won prize.
The goal of the campaign is Vicksburg, and Grant has never lost sight of that. The capture of Vicksburg opens the Mississippi River and it cuts the Confederacy in-two. The capture of Jackson is merely a step on the road to that goal. Grant does not have the men to hold the place and take Vicksburg. So, even while Grant’s commanders celebrate in the Bowman house he is ordering McPherson’s men on the road again, to rejoin McClernand’s Corps, now almost at Clinton. Sherman is to leave two divisions in Jackson, but only long enough to destroy track along the Central Mississippi Railroad, and any manufacturing in the city. By the time Jackson is returned to the Confederacy, Grant means it to be almost worthless.
That night, six miles North of Jackson, and with the telegraph lines cut at Clinton and, now, at Jackson too, General Johnston sends written dispatches to Pemberton in Vicksburg, telling him of the capture of Jackson. But he also see’s an opportunity in this calamity. He now commands 11,000 men, and in 24 hours he will have 15,000. He knows that Grant does not have enough men to hold Jackson and take Vicksburg. So he tries, once more, to prod Pemberton, into action against Grant, asking, “Can he supply himself from the Mississippi? Can you not cut him off from it, and above all, should he be compelled to fall back for want of supplies, beat him? As soon as the re-enforcements are all up, they must be united to the rest of the army. I am anxious to see a force assembled that may be able to inflict a heavy blow upon the enemy." But what Johnston and Pemberton do not yet realize is that Grant is two steps ahead of them. There is no supply line for Pemberton to cut.