No. 147. Report of Lieutenant Colonel Cornelius D. Westrbrook, One hundred and twentieth New York Infantry.

CAMP NEAR FALMOUT, VA., May 7, 1863.

MAJOR: I have the honor to forward and official report of the recent action and movements of this regiment, with a recapitulation of casualties.

The regiment broke camp on the afternoon of the 28th altum, and moved with the brigade down the river about 4 miles, where it encamped for the night.

It moved again in the morning about half a mile, and encamped for the day and following night.

The regiment was mustered the next day, on the morning of the 30th ultimo. The paymaster also commenced paying the regiment on the December and February pay-rolls; but, after completing the payment of four compliances, was interrupted by an order to march. The regiment marched again with the brigade 12 miles up the river, when it encamped for the night.

On the next morning (1st instant), it marched to the United States Ford, crossed on the pontoon bridge, halted for dinner, and marched in the afternoon 2 miles in a southerly direction, when it was ordered on picket. While positing the pickets, the regiment was recalled to the brigade, and marched to a position near the front, where it encamped for the night and until sundown on the 2nd, when it was ordered to the front. Here also the knapsacks and a portion of the arms were stacked, by order, under a guard, and left. No casualties occurred from the shot and shell of the enemy.

At sundown it was marched hastily with the brigade up the Plank road to the front. While following the Second Regiment, I was ordered by General Berry in person to file off to the right in the woods, into which also the other regiments troops. At a distance of 300 yards form the Plank road, the regiment obtained al line, in company with other regiments of the brigade, with the Second Excelsior on our right and the Fifth Excelsior on our left, and moved to the front in line of battle. The whole line was moved several times, and the movement of our own regiment confused by contradictory orders coming up from the left and the right. Finally, late in the evening, the connection of lines was perfected by retiring our right wing to meet an advance of the left wing of the Second.

Under an order to barricade, I sent our pioneers back for their axes, and succeeded in constructing an efficient barricade of logs 3 feet in height, and an abatis of small trees in front, not high enough, however, to intercept our fire. No casualty occurred from the cannonading and volley firing of the night. A company of skirmishers (Company D) was thrown forward, and also scouts, one of which has not since returned to us.

At daybreak on the morning of the 3rd, we were ordered to march out by the left flank, following the Fifth Regiment. After marching a short distance, we were ordered back again behind our barricade. A fresh company of skirmishers (Company B) was thrown out. Immediately after they had taken their position, the attack of the enemy commenced. In a short time the skirmishers were driven in, with a loss of 2 men killed and 45 wounded.