Pemberton’s retreating troops burned the bridge over the Big Black River, but McClernand’s engineers worked through the night under sniper fire to replace it. They continued the pursuit on the 18th.
From McClernand’s report in the Official Records:
Driven across the river, the enemy made a feeble stand to cover his trains and retreat upon Vicksburg, but several hours before sunset was dislodged by my forces, leaving tents, a considerable quantity of clothing and other stores, together with a large number of small arms, a smoking ruin.
During the following night and morning a bridge was thrown across the Big Black by the pioneer corps under Captain Patterson.
On the morning of the 18th, I crossed with Generals Osterhaus’, Smith’s, and Carr’s DIVISIONS, of my corps, and took up the line of march for Vicksburg, 12 miles distant. General Smith’s DIVISION led, followed by Generals Osterhaus and Carr, on the Jackson and Vicksburg road to Saint Albans, and thence by a cross road and the Baldwin’s Ferry road at Four Mile Creek, arriving there about sunset, and resting for the night 4 miles from Vicksburg. Several prisoners and wagons were captured during the march. General Osterhaus resumed command of the NINTH DIVISION on the WEST bank of Big Black, and General Lee was assigned to the command of the First Brigade of that DIVISION during the absence of General Garrard, who had been ordered to report to General Prentiss, at Helena.