Other attacks were made with great vigor by other brigades, Sherman keeping up meantime a furious artillery fire to occupy the attention of the enemy. At one time it was announced that McClernand had captured three of the Rebel forts and that his flag floated over the stronghold of Vicksburg; but this proved untrue. On the strength of this report, however, Sherman ordered General Mower to charge with his brigade. This was done, with results similar to those at first achieved, the colors being planted by the side of those of the first storming party. There they remained until after nightfall, when they were withdrawn by Sherman's orders.
This assault failed simply because the enemy's works were too strong to be taken in that way. The Rebels were able to mass at every point all the men that were needed to defend it, while the nature of the ground made it impossible for more than a few of the Union troops to advance at once. Grant was not, however, discouraged. If he could not take Vicksburg in one way, he would take it in another. If the direct assult failed, he would see what could be done by a siege. At the siege operations the troops worked diligently and cheerfully. The intrenchments were pushed steadily forward until the evening of July 3d. At that time the saps were close to the enemy's ditch and the mines were under his parapet. Everything was ready for the final attack. Grant's army had been strengthened by various reinforcements. Indeed it had been strengthened so much that he was able to spare Sherman from the immediate work of the siege. So he placed him in command of the Ninth Corps at Haines's Bluff to watch J. E. Johnston. The latter had collected a large army at Jackson with the intention of attacking Grant's force in the rear, and thus raising the siege of Vicksburg. Sherman took up a strong position and easily held him at bay. Johnston, however, became desperate in his desire to save Vicksburg from capture, and on June 29th moved out to try conclusions with Sherman. But before his preparations for battle were complete, on July 4th, 1863, Vicksburg surrendered.
In his official report of the operations around Vicksburg, dated July 6th, Grant spoke thus of Sherman's work in holding the enemy at bay: "Johnston, however, not attacking, I determined to attack him the moment Vicksburg was in our possession, and accordingly notified Sherman that I should again make an assult on Vicksburg at daylight on the 6th, and for him to have up supplies of all descriptions ready to move upon receipt of orders, if the assult should prove a success. His preparations were immediately made, and when the place surrendered on the 4th, two days earlier than I had fixed for the attack, Sherman was found ready, and moved at once with a force increased by the remainder of both the Thirteenth and Fifteenth Army Corps, and is at present investing Jackston, where Johnston has made a stand."