The next day (July 4, 1863) Vicksburg surrendered, and orders were given for at once attacking General Johnston.  The Thirteenth Corps (General Ord) was ordered to march rapidly, and cross the Big Black at the railroad-bridge; the Fifteenth by Mesainger’s, and the Ninth (General Parker) by Birdsong’s Ferry-all to converge on Bolton.  My corps crossed the Big Black during the 5th and 6th of July, and marched for Bolton, where we came in with General Ord’s troops; but the Ninth Corps was delayed in crossing at Birdsong’s.  Johnston had received timely notice of Pemberton’s surrender, and was in full retreat for Jackson.  On the 8th all our troops reached the neighborhood of Clinton, the weather fearfully hot, and water scarce.  Johnston had marched rapidly, and in retreating had caused cattle, hogs, and sheep, to be driven into the ponds of water, and there shot down; so that we had to haul their dead and stinking carcasses out to use the water.  On the l0th of July we had driven the rebel army into Jackson, where it turned at bay behind the intrenchments, which had been enlarged and strengthened since our former visit in May.  We closed our lines about Jackson; my corps (Fifteenth) held the centre, extending from the Clinton to the Raymond road; Ord’s (Thirteenth) on the right, reaching Pearl River below the town; and Parker’s (Ninth) the left, above the town.

On the 11th we pressed close in, and shelled the town from every direction.  One of Ords brigades (Lauman’s) got too close, and was very roughly handled and driven back in disorder.  General Ord accused the commander (General Lauman) of having disregarded his orders, and attributed to him personally the disaster and heavy loss of men.  He requested his relief, which I granted, and General Lauman went to the rear, and never regained his division.  He died after the war, in Iowa, much respected, as before that time he had been universally esteemed a most gallant and excellent officer.  The weather was fearfully hot, but we continued to press the siege day and night, using our artillery pretty freely; and on the morning of July 17th the place was found evacuated.  General Steele’s division was sent in pursuit as far as Brandon (fourteen miles), but General Johnston had carried his army safely off, and pursuit in that hot weather would have been fatal to my command.

Reporting the fact to General Grant, he ordered me to return, to send General Parkes’s corps to Haines’s Bluff, General Ord’s back to Vicksburg, and he consented that I should encamp my whole corps near the Big Black, pretty much on the same ground we had occupied before the movement, and with the prospect of a period of rest for the remainder of the summer.  We reached our camps on the 27th of July.

Meantime, a division of troops, commanded by Brigadier-General W. Sooy Smith, had been added to my corps.  General Smith applied for and received a sick-leave on the 20th of July; Brigadier-General Hugh Ewing was assigned to its command; and from that time it constituted the Fourth Division of the Fifteenth Army Corps.