No. 188. Report of Captain John D. O'Connell, Fourteenth U. S. Infantry.

CAMP NEAR FALMOUTH, VA., December 20, 1862.

SIR: In compliance with orders, I have the honor to make the following report of the part taken in the late fight at Fredericksburg, Va., by this regiment during the seven days commencing on the 11th and ending on the 17th instant:

The First Battalion, numbering 256, and the Second Battalion, 153 men, including commissioned officers, the former and regiment commanded by me, and the latter part of the time by Captain Overton, and the remainder of it by Captain Thatcher, left this camp about 6 o'clock on the morning of the 11th instant, and marched with the brigade, halting about one hour on the road, to a position about 1 1/2 miles from Falmouth, from which there was a good view of the Rappahannock, the city of Fredericksburg, and the enemy's works beyond it. Here the brigade was formed in column by battalion. In this position I remained until the evening of the 13th instant, when ordered across the river to the point beyond the city where the fighting was then going on. On approaching the bridge thrown over the river, the column was exposed to a pretty severe and constant fire from the enemy's heavy guns, which was kept up until the division had completed the crossing. The command having deposited its knapsacks in the lower part of the town, was moved rapidly to the front, expecting and anxious to participate in the fight. On arriving in the front, orders were received to prepare to charge the enemy's works, which were to be taken at all hazards. The brigade was immediately drawn up in line, and moved forward to a ditch partly filled with water, when another order was received to halt and hold the ditch. By this time night had well set in, and but little could be seen in our front.

About 10 o'clock this evening I was directed to furnish a picket guard to go to the front. Companies B and H, First Battalion, the former commanded by Lieutenant Walker and the latter by Lieutenant Moroney, were detailed for this purpose. About 11 o'clock the same evening the brigade was moved to the front, to relieve a part, I believe, of Couch's division, then on picket duty. I was posted on the right of the road, the left of the Second Battalion resting near a brick house on the road, and about 150 yards from the enemy's rifle-pits. Having been up this position, I went froward, and found out the exact position of Companies B and H, detached, as stated above, and connected that line of pickets with those thrown out from the Twelfth Infantry, posted on my right. Before good daylight I drew in all my pickets, except such as could be sheltered from the enemy's fire, and were necessary to watch his movements. While drawing in these pickets, 3 were wounded by the enemy's fire. This position we held about twenty-four hours, under almost a continuous fire of musketry from the enemy's rifle-pits, with occasional shots from heavy guns during the daylight, when relieved by a volunteer command. During the day I had but 1 man wounded, the nature of the ground being such that, with a little care, the regiment was made comparatively safe. My pickets at first did not fire, from orders I received from the brigade commander, but afterward I allowed them to fire, but I fear did but little damage to the enemy, owing