Lee had weakened the other parts of his line to meet this movement of Hancock’s, and I determined to take advantage of it.  Accordingly in the morning, orders were issued for an attack in the afternoon on the centre by Warren’s and Wright’s corps, Hancock to command all the attacking force.  Two of his divisions were brought to the north side of the Po.  Gibbon was placed to the right of Warren, and Birney in his rear as a reserve.  Barlow’s division was left south of the stream, and Mott of the same corps was still to the left of Wright’s corps.  Burnside was ordered to reconnoitre his front in force, and, if an opportunity presented, to attack with vigor.  The enemy seeing Barlow’s division isolated from the rest of the army, came out and attacked with fury.  Barlow repulsed the assault with great slaughter, and with considerable loss to himself.  But the enemy reorganized and renewed the assault.  Birney was now moved to the high ground overlooking the river crossings built by our troops, and covered the crossings.  The second assault was repulsed, again with severe loss to the enemy, and Barlow was withdrawn without further molestation.  General T. G. Stevenson was killed in this move.

Between the lines, where Warren’s assault was to take place, there was a ravine grown up with large trees and underbrush, making it almost impenetrable by man.  The slopes on both sides were also covered with a heavy growth of timber.  Warren, before noon, reconnoitred his front twice, the first time with one and the second with two divisions.  He was repulsed on both occasions, but gained such information of the ground as to induce him to report recommending the assault.

Wright also reconnoitred his front and gained a considerably advanced position from the one he started from.  He then organized a storming party, consisting of twelve regiments, and assigned Colonel Emory Upton, of the 121st New York Volunteers, to the command of it.  About four o’clock in the afternoon the assault was ordered, Warren’s and Wright’s corps, with Mott’s division of Hancock’s corps, to move simultaneously.  The movement was prompt, and in a few minutes the fiercest of struggles began.  The battle-field was so densely covered with forest that but little could be seen, by any one person, as to the progress made.  Meade and I occupied the best position we could get, in rear of Warren.

Warren was repulsed with heavy loss, General J. C. Rice being among the killed.  He was not followed, however, by the enemy, and was thereby enabled to reorganize his command as soon as covered from the guns of the enemy.  To the left our success was decided, but the advantage was lost by the feeble action of Mott.  Upton with his assaulting party pushed forward and crossed the enemy’s intrenchments.  Turning to the right and left he captured several guns and some hundreds of prisoners.  Mott was ordered to his assistance but failed utterly.  So much time was lost in trying to get up the troops