MAY 31-JUNE 1, 1862.-Battle of Fair Oaks, or Seven Pines, Va.

Report of Colonel William W. H. Davis, One hundred and fourth Pennsylvania Infantry.

DOYLESTOWN, PA., June 25, 1862.

CAPTAIN: I have the honor to report the part taken by my regiment in the battle of Fair Oaks, or Seven Pines, fought on the 31st day of May:

About 12.30 o'clock noon an aide-de-camp of General Casey came to my quarters on the Nine-Mile Road and ordered me to get my regiment under arms immediately. In a few minutes afterward it was formed on the color line cut in the bushes. I had but eight companies in line, the other two being on picket. My effective strength was a little less than 400 men. Shortly after we were formed another aide came to my quarters with orders to move the regiment out by the left flank to a clearing between the Nine-Mile and Williamsburg roads to support Spratt's battery of 10-pounders. We marched along a path I had caused to be cut through the bushes a few days before, and formed line in the edge of the timber a little to the right and rear of the battery. I had hardly dressed my line when I was ordered to advance my regiment into the clearing in front, which was done as quickly as possible. To attain this position we had to cross the abatis formed to prevent the approach of the enemy, and my line was a considerable distance in front of the battery I was sent to support. The right of the regiment rester on the timber which flank in on that side. Skirmishing had been going on before we arrived on the field, and soon afterward the skirmishers came running in, pressed back by the enemy. The enemy's bullets fell in my ranks while the line was being formed. Nevertheless, the regiment was dressed with the precision of a dress parade. We opened with a general volley, the first fired that day, which announced the action commenced in earnest, and until it was concluded there was a perfect rattle of musketry and roar of artillery. The men began to fall, killed and wounded, but there was no faltering. Every officer and man stood up to his work. Seeing a movement of the enemy on our right as though about to flank us in that direction, Companies A and D were pushed into the timber to prevent it. The enemy now came out of the timber and pressed down upon us in overwhelming numbers. Their fire was withering. We had now been under fire about an hour and a half, and our ranks were much thinned. The enemy was now pressing me hard in front and on the right flank, and their fire had approached so near as to endanger the battery. Under these circumstances I ordered a charge, the regiment at the word springing forward and advancing with a loud hurrah toward the enemy. It had the effect of gaining time and enabled us to hold the enemy longer in check. Seeing I must relinquish my ground unless re-enforced, I sent Lieutenant Ashenfelter to General Casey on the Williamsburg road, with the request that he would send me a regiment to support the One hundred and fourth. He passed twice between the two armies unharmed. He sent word that if I could hold my position a few minutes longer he would re-enforce me. The fight had now raged two hours with great fierceness, and almost one-half my regiment had fallen. In this part of the field the One hundred and fourth was contending singlehanded with overwhelming numbers. We could hold our ground no longer, and the superior numbers of the enemy and the want of the promised supports compelled us to retire. The men left the ground slowly and sullenly and retired down the Nine Mile Road to near where it joins the