McPherson moved on the 13th to Clinton, destroyed the railroad and telegraph, and captured some important despatches from General Pemberton to General Gregg, who had commanded the day before in the battle of Raymond. Sherman moved to a parallel position on the Mississippi Springs and Jackson road; McClernand moved to a point near Raymond.
The next day Sherman and McPherson moved their entire forces toward Jackson. The rain fell in torrents all the night before, and continued until about noon of that day making the roads at first slippery and then miry, notwithstanding, the troops marched in excellent order without straggling and in the best of spirits about fourteen miles, and engaged the enemy about 12 o'clock, m., near Jackson. McClernand occupied Clinton with one division, Mississippi Springs with another, Raymond with a third, and had his fourth division and Blair's division of Sherman's corps with a wagon train still in the rear near New Auburn, while McArthur with one brigade of his division of McPherson's corps was moving toward Raymond on the Utica road. It was not the intention to move these forces any nearer Jackson, but to have them in a position where they would be in supporting distance if the resistance at Jackson should prove more obstinate than there seemed reason to expect.
The enemy marched out the bulk of his force on the Clinton road and engaged McPherson's corps about two and a half miles from the city. A small force of artillery and infantry took a strong position in front of Sherman, about the same distance out. By a determined advance of our skirmishers these latter were soon driven within their rifle-pits just outside the city. It was impossible to ascertain the strength of the enemy at this part of the line in time to justify an immediate assault; consequently McPherson's two divisions engaged the main bulk of the rebel garrison at Jackson, without further aid than the moral support given them by the knowledge the enemy had a force to the south side of the city and the few infantry and artillery of the enemy posted there to impede Sherman's progress. Sherman soon discovered the weakness of the enemy by sending a reconnoitering party to his right, which also had the effect of causing the enemy to retreat from this part of his line. A few of the artillerists, however, remained in their places, firing upon Sherman's troops, until the last moment, evidently instructed to do so, with the expectation of being captured in the end. On entering the city it was found that the main body of the enemy had retreated north, after a heavy engagement of more than two hours with McPherson's corps, in which he was badly beaten. He was pursued until near night, but without further damage to him.
During that evening I learned that General Johnston, as soon as he satisfied himself that Jackson was to be attacked, had ordered Pemberton peremptorily to march out from the direction of Vicksburg and attack our rear. Availing myself of this information, I immediately issued orders to McClernand and Blair, of Sherman's corps, to face their troops towards Bolton, with a view of reaching Edward's Station, marching on different roads converging near Bolton. These troops were admirably located for such a move. McPherson was ordered to retrace his steps early in the morning of the 15th on the Clinton road. Sherman was left in Jackson to destroy the railroads, bridges, factories, workshops, arsenals, and everything valuable for the support of the enemy. This was accomplished in the most effectual manner.
On the afternoon of the 15th I proceeded as far west as Clinton, through which place McPherson's corps passed to within supporting distance of Hovey's division of McClernand's corps, which had moved that day on the same road to within one and a half mile of Bolton. On reaching Clinton, at 4.45 p.m., I ordered McClernand to move his command early the next morning toward Edward's Station, marching so as to feel the enemy, if he encountered him, but not to bring on a general engagement unless he was confident he was able to defeat him; and also to order Blair to move with him.
About five o'clock on the morning of the 16th, two men, employees on the Jackson and Vicksburg railroad, who had passed through Pemberton's army the night before, were brought to my headquarters. They stated Pemberton's force to consist of about eighty regiments, with ten batteries of artillery, and that the whole force was estimated by the enemy at about twenty-five thousand men. From them I also learned the positions being taken up by the enemy, and his intention of attacking our rear. I had determined to leave one division of Sherman's corps one day longer in Jackson, but this information determined me to bring his entire command up at once, and I accordingly dispatched him at 5.30 a.m. to move with all possible speed until he came up with the main force near Bolton. My despatch reached him at 7.10 a.m., and his advance division was in motion in one hour from that time. A despatch was sent to Blair at the same time, to push forward his division in the direction of Edward's Station with all possible dispatch. McClernand was directed to establish communication between Blair and Osterhaus, of his corps, and keep it up, moving the former to the support of the latter. McPherson was ordered forward at 5.45 a.m. to join McClernand, and Lieutenant-Colonel Wilson, of my staff, was sent forward to communicate the information received, and with verbal instructions to McClernand as to the disposition of his forces. At an early hour I left for the advance, and on arriving at the crossing of the Vicksburg and Jackson railroad with the road from Raymond to Bolton, I found McPherson's advance and his pioneer corps engaged in rebuilding a bridge on the former road that had been destroyed by the cavalry of Osterhaus's division that had gone into Bolton the night before. The train of Hovey's division was at a halt, and blocked up the road from further advance on the Vicksburg road. I ordered all quartermasters and wagonmasters to draw their teams to one side and make room for the passage of troops. McPherson was brought up by this road. Passing to the front, I found Hovey's division of the thirteenth army corps at a halt, with our skirmishers and the enemy's pickets near each other. Hovey was bringing his troops into line, ready for battle, and could have brought on an engagement at any moment. The enemy had taken up a very strong position on a narrow ridge, his left resting on a height where the road makes a sharp turn to the left approaching Vicksburg. The top of the ridge and the precipitous hill-side to the left of the road are covered by a dense forest and undergrowth. To the right of the road the timber extends a short distance down the hill, and then opens into cultivated fields on a gentle slope and into a valley extending for a considerable distance. On the road and into the wooded ravine and hill-side Hovey's division was disposed for the attack. McPherson's two divisions, all of his corps with him on the march from Milliken's Bend (until Ransom's brigade arrived that day after the battle), were thrown to the right of the road properly speaking, the enemy's rear. But I would not permit an attack to be commenced by our troops until I could hear from McClernand, who was advancing with four divisions, two of them on a road intersecting the Jackson road about one mile from where the troops above described were placed, and about the centre of the enemy's line; the other two divisions on a road still north and nearly the same distance off.
I soon heard from McClernand, through members of his staff and my own, whom I had sent to him early in the morning, and found that by the nearest practicable route of communication he was two and a half miles distant. I sent several successive messages to him to push forward with all rapidity. There had been continuous firing between Hovey's skirmishers and the rebel advance, which by 11 o'clock grew into a battle. For some time this division bore the brunt of the conflict, but finding the enemy too strong for them, at the instance of Hovey I directed first one and then a second brigade from Crocker's division to re-enforce him. All this time Logan's division was working upon the enemy's left and rear and weakened his front attack most wonderfully. The troops here opposing us evidently far outnumbered ours. Expecting McClernand momentarily with four divisions, including Blair's, I never felt a doubt at the result. He did not arrive, however, until the enemy had been driven from the field, after a terrible contest of hours, with a heavy loss of killed, wounded and prisoners, and a number of pieces of artillery. It was found afterward that the Vicksburg road, after following the ridge in a southerly direction for about one mile and to where it intersected one of the Raymond roads, turns almost to the west, down the hill and across the valley in which Logan was operating on the rear of the enemy. One brigade of Logan's division had, unconscious of this important fact, penetrated nearly to this road and compelled the enemy to retreat to prevent capture. As it was, much of his artillery and Loring's division of his army was cut off, besides the prisoners captured. On the call of Hovey for more re-enforcements, just before the rout of the enemy commenced, I ordered McPherson to move what troops he could by a left flank around to the enemy's front. Logan rode up at this time and told me that if Hovey could make another dash at the enemy he could come up from where he then was and capture the greater part of their force. I immediately rode forward and found the troops that had been so gallantly engaged for so many hours withdrawn from their advanced position and were filling their cartridge boxes. I directed them to use all dispatch and push forward as soon as possible, explaining to them the position of Logan's division. Proceeding still further forward, expecting every moment to see the enemy, and reaching what had been his line, I found he was retreating. Arriving at the Raymond road, I saw to my left and on the next ridge a column of troops which proved to be Can's division and McClernand with it in person; and to the left of Carr, Osterhaus's division soon afterward appeared with his skirmishers well in advance. I sent word to Osterhaus that the enemy was in full retreat, and to push up with all haste. The situation was soon explained, after which I ordered Carr to pursue with all speed to Black river, and across it if he could, and to Osterhaus to follow. Some of McPherson's troops had already got into the road in advance, but having marched and engaged the enemy all day they were fatigued, and gave the road to Carr who continued the pursuit until after dark, capturing a train of cars loaded with commissary and ordnance stores and other property.
The delay in the advance of the troops immediately with McClernand was caused, no doubt, by the enemy presenting a front of artillery and infantry where it was impossible, from the nature of the ground and the density of the forest, to discover his numbers. As it was, the battle of Champion's Hill or Baker's Creek was fought mainly by Hovey's division of McClernand's corps and Logan's and Quinby's divisions (the latter commanded by Brigadier-General M. M. Crocker) of McPherson's corps.
Ransom's brigade, of McPherson's corps, came on to the field where the main battle had been fought immediately after the enemy had begun his retreat.
Word was sent to Sherman, at Bolton, of the result of the day's engagement, with directions to turn his corps toward Bridgeport, and to Blair to join him at this latter place.