The simulataneous appearance of the enemy's battalions on so long a line led me to believe that they had been lying in position for some time behind the woods in our front, fully prepared for us, and that it was their left wing around our right, and thus to cut us off from the town. Amovement to the rear became at once necessary, but before any orders to that effect could be transmitted, my whole line was engaged, and the Second Brigade, First Division, whose flank had been most exposed in consesquence of the advance, fell back in considerable disorder. Unfortunately, General Barlow, who had been directing the movements of his troops with the most praiseworthy coolness and intrepidity, unmindful of the shower of bullets around, was severely wounded, and had to be carried off the battlefield. The command of the First Division devolved upon General Ames. It was now of the highest importance to hold the Middletown and Mummasburg roads. Had the brigade of the Second Division been then at the appointed place, I would have ordered it to charge upon the flanking columns of the enemy, taking them in flank and rear; but that brigade not being there, all I could do was to endeavor to rally the Second Brigade, of the First Division, and to hold the ground west of those roads until the other brigades could be taken back. The enemy, however, pressing on with great vigor, that brigade could be rallied only in part, and the First Brigade, of the First Division, finding its right flank uncovered, was forced back also, not however, without hotly contesting every inch of ground. At that moment it was reported to me that the right wing of the First Corps had been pressed back, and one of Major-General Doubleday's aides brought me a request for a few regiments to be sent over to its assistance, which it was, under the circumastances, impossible for me to do. I received also a report from the Third Division, stating that it was flanked on the left. At the same time your order reached me to withdraw to the south side of the town, and to occupy the position on and near Cemetery Hill previously chosen by your. While I was doing my utmost, assisted by the officers of my staff, to rally what was within my reach of the First Division, in order to check the enemy' s advance upon my right and to hold the entrance of the town, the First Brigade, of the Second Division, under Colonel Cosster, at last made its appearance. I lead it out of the town, and ordered it to deploy on the right of the junction of the roads near the railroad depot, which the enemy was fast approaching. It was now too late for executing the offensive movement upon the enemy's left flank, which I had originally contemplated, and which might have been made to great advantage ten minutes before, but the brigade, assisted by a battery, succeeded, at all events, in checking the enemy long enough to permit the First Division to enter the town without being seriously molested on its retreat. The Third Division had mean while to sustain a furious attack. According to orders, it fell back toward the town in good order, contesting the ground step by step with the greatests firmnness. In this part of the action, which was almost a hand-to-hand struggle, officers and men showed the highest courage and determination. Our loss was extremely severe. The Second Brigade, Third Division, lost all its regimental commanders; several regiments nearly half their number in killed and wounded. Being flanked right and left, the situation of that division was most trying. The retreat throught the town, protected by part of our artillery,