The pursuit was continued to Edwards's Depot that night, the leading troops capturing at that place an ammunition-train of ten or twelve railroad-cars. At dawn of the 17th the pursuit was renewed in the direction of Vicksburg; and by seven o'clock McClernand's advance, under Osterhaus and Carr, came up with the Confederate rear-guard posted in strong intrenchments nearly a mile in extent, covering the railroad and military bridges across the Big Black. These divisions were developed without delay under a strong fire from the Confederate artillery, during which Osterhaus was wounded. Carr held the right, his right brigade, commanded by General Lawler, resting upon the Big Black. After some desultory artillery firing and skirmishing, Lawler found a weak place on the extreme left of the enemy's works, and lost no time in leading his brigade, composed of Iowa and Wisconsin men, to the assault. Advancing across an open field several hundred yards in width, they received a deady fire, but without faltering they rushed gallantly through the ditch and over the breastworks, sweeping away all opposition and capturing eighteen guns and nearly two thousand prisoners. In this gallant affair Colonel Kinsman of the Twenty-third Iowa was killed, and Colonel Merrill of the Twenty-first was wounded - both, while cheering forward their men in the most conspicuous manner.
This put an end to the campaign in the open field. Pemberton immediately abandoned his camp on the Big Black, and retreated in disorder to Vicksburg. Johnston had gone in the direction of Canton, but did not attempt a diversion in Pemberton's favor, though he might have fallen upon Sherman's flank and harassed him considerably.
During the night four floating bridges were built across the Big Black by the troops under the direction of the engineer officers. McClernand built one out of the ruins of the railroad bridge, near the railroad crossing; McPherson built two farther up the river, one of timber obtained by pulling down cotton-gin houses, the other of cotton-bales rafted together; while Sherman made his of the india-rubber pontoons. After nightfall Grant rode up the river to see Sherman, whom he found at Bridgeport engaged in crossing his command. The two commanders crossed the bridge and seated themselves on a fallen tree, in the light of a pile of burning fence-rails, and had a friendly conference, while the eager and swift-marching men of the Fifteenth Corps filed by them and disappeared in the darkness. Grant recounted the results of the campaign and detailed his plans for the next day, after which he returned through the forest to his own headquarters.
On the next day, May 18th, the army marched by the various roads to the rear of Vicksburg, and after slight skirmishing drove the Confederate pickets inside of their works. Communication by signal was opened at once with the gunboats and transports lying above Vicksburg, and measures were taken to establish communications with Yazoo River. The enemy had already evacuated Haines's Bluff, and the navy took possession of the place, and proceeded to burn the gun-carriages, camps, and stores, and to blow up the magazines. This, however, was done in mistaken zeal, and inflicted an actual damage upon the Federal army rather than upon the enemy.
Within these eighteen days Grant had won five battles; taken 40 field-guns, many colors and small arms, and nearly 5000 prisoners; killed or wounded 5200 Of the enemy; separated their armies, in the aggregate nearly 60,000 strong; captured one fortified capital city; compelled the abandonment of the strong positions of Grand Gulf and Haines's Bluff, with their armament Of 20 heavy guns; destroyed the railroads and bridges; and made the investment of Vicksburg complete. In doing this McPherson's and McClernand's corps had marched an average Of 156 miles, while Sherman's had marched 175 miles. During this time the united strength of these three corps did not exceed 45,000 men. There is nothing in history since Hannibal invaded Italy to compare with the surpassing boldness and vigor of the generalship displayed by Grant in conducting this campaign.
“Do all thou doest as unto Christ, as immediately dealing with Christ Jesus, as if he were looking on thee, and though on him, and fetch all thy strength from him.”
–Thomas Wilcox, A Choice Drop of Honey