No. 190. Report of Captain Salem S. Marsh, Second U. S. Infantry, commanding Battalion of First and Second U. S. Infantry.

CAMP NEAR POTOMAC CREEK, VA., December 19, 1862.

GENERAL: I have the honor to report that, according to orders received, the battalion (Second and First Infantry), consisting of nine companies of the Second and one of the First Infantry, numbering 13 commissioned officers and 286 enlisted men, left camp near Potomac Creek on the morning of the 11th instant, and bivouacked near Falmouth. The battalion remained in that position until 2.15 p.m. on the 13th, when the brigade marched and formed under cover near Phillips house, and close to the pontoon bridge.

About 3 p.m. the battalion moved across the Rappahannock with the brigade, and marched through Fredericksburg, the brigade forming in column of battalion closed in mass at 4.30 p.m. on the left of the road, on the outskirts of the town. At 5 p.m. the battalion was ordered to move to the crest of the hill, 100 yards in advance of its former position, to protect the withdrawal of a battery. During this forward movement the battery was withdrawal, and the battalion halted in rear of a ditch, the banks of which afforded good cover, where it remained until 10 p.m., when again ordered forward with the brigade about 600 yards in advance of the latter position, and 100 yards from the stone wall occupied by the enemy.

On the morning of the 14th, the enemy opened a murderous fire, driving in our pickets. The battalion was ordered to lie down behind a slight elevation of ground (about 1 foot), giving some protection, where it was obliged to remain until dark, under a terrific fire, the plane of the enemy's fire passing not more than a foot over the ground on which they lay. Soon after the enemy opened fire, orders were given not to fire, orders were given not to fire, and to hold ground, if possible, without bringing on a general engagement. The firing of the enemy ceased at dark, and the battalion received orders to hold itself in readiness to be relieved.

At 11 p.m. the battalion was relieved, and marched to Fredericksburg, where it bivouacked in one of the streets running parallel with the river, remaining there until 11 p.m. the 15th, when ordered one block forward, parallel with its last position.

It moved from the latter position at about 6 a.m. the 16th, marched across the river, and bivouacked on the same ground as on the night of the 11th and 12th.

On the morning of the 17th, the battalion marched and took up its old position in camp near Potomac Creek. The peril of our position was only disclosed by the right dawn of day, that revealed us to the unerring aim of the enemy's sharpshooters. The slightest exposure elicited from them a shower of bullets, one or more of which proved fearfully accurate. As quietly and calmly as human nature was capable of, did the battalion await the night that should end the ordeal they were required to pass through. Never did discipline shine more resplendently; never was the reputation of a regiment more nobly, more incontrovertibly confirmed than that of the Second; never could a battalion more signally gain the title of brave and excellent soldiers than this one on that ever to be remembered Sabbath, December 14.

I am, general, very respectfully, your obedient servant,

SALEM S. MARSH,

Captain Second Infantry, Commanding Battalion.

General L. THOMAS, Adjt. General U. S. Army, Washington, D. C.