A few days after the battle of Fair Oaks our pickets, were withdrawn from the position they occupied after the battle. This was in consequence of the difficult character of the swamp and the thick undergrowth. Our pickets being so near, necessitated keeping the troops more on the alert than would have been necessary had they been out the usual distance, thus depriving them of necessary rest. All our efforts to extend our pickets were opposed by the rebels in the most determined manner, occasioning a daily loss on both sides.

The evening of the 24th I received orders from the commanding general to put my whole corps under arms and extend my picket line to the requisite distance, that General Sumner's left would advance at the same time, and a demonstration with artillery would be made still farther to the right. The necessary orders were given that night.

At 8 o'clock a.m., the hour fixed upon, I went to the front. The troops were soon in position, and the advance commenced. General Hooker has so fully explained the position of his division it is not necessary to repeat it here. Information was sent to General Richardson on the right and to General Kearny on the left of our advance to enable them to push forward their pickets at the same time. The enemy from the beginning opposed the advance of General Sickles' brigade on both side of the Williamsburg road. The enemy were, however, steadily driven back some 600 yards on our right half a mile in front of General Grover's brigade and near a mile on the front of General Kearny's division.

At this time General Hooker's division was opposed by three to one, and the enemy held the woods so pertinaciously that no further progress could be made without re-enforcements. This I telegraphed to general headquarters, and ordered up General Birney's brigade as a support. Just as this brigade reported to General Hooker he received a telegram from General Marcy, intended for me, directing him to fall back. The order was given, but the enemy was contended to hold me ground on which they were.

As the commanding general was coming to judge for himself about pressing farther, I directed the troops to halt and hold what we had gained. At about 1 o'clock p.m. the general arrived. After learning the position of affairs he directed the attack to be renewed. Ordering up General Palmer's brigade, General Couch's division, of General Keyes' corps, as a support, should it be needed, I sent Captain De Russy forward with a section of a battery to dislodge the enemy. This was handsomely done, and the rebels were driven into the open field and to the woods beyond. In the edge of the woods were several rebel camps, which were shelled. Our troops were now in the position we wished to hold from right to left. Measures were taken to establish a picket line and withdraw the troops to their former lines.

Whilst this was being done (at 5 o'clock p.m.) the commanding general received a telegram requiring his presence on our extreme right and left immediately. Everything remained quiet for half an hour, when the rebels made a sudden attack on the right of General Kearny's line of General Robinson's front. The attack was so vigorous that a portion of the line gave way. I had previously ordered up General Birney's brigade to relieve General Grover's, as the latter had already finished their tour in the advance.

This brigade being at hand I immediately directed it to relief of General Robinson. One regiment, the --, enabled him to repulse the enemy and again occupy our advanced line. By 9 o'clock p.m. all was quiet, and I returned to my headquarters. All the brigades of