The force consisted of the Sixth regiment, Colonel W. W. Rickets; Ninth, Colonel C. F. Jackson; Tenth, Colonel John S. McCalmont; Twelfth, Colonel John H. Taggart. The regiment of riflemen known as the Bucktails, Lieutenant-Colonel Thomas L. Kane; a battery of two twenty-four-pounders and two twelve-pounders, commanded by Captain Easton, and a detachment of cavalry from Colonel Bayard’s regiment, also accompanied the expedition. Each regiment was strongly represented, and there were about four thousand men in the expedition. The order for march was received on Thursday evening, the men being directed to take with them one day’s rations. The morning was clear, and rather cold, with a slight mist around the sun, and a thin layer of frost whitening the road and coating the grass. The Bucktails were assigned the advance of the infantry column, the cavalry preceding as scouts, and battery being in reserve. Colonel Taggart’s regiment brought up the rear. A number of teams were also in company. Each regiment had two companies of flankers thrown out, on either side of the column, to scour the woods, search the thickets, and prevent the column from falling into an ambuscade. They halted at Difficult Creek, a narrow stream, with a heavy stone bridge. The stream is fordable, the average width being thirty feet. The march continued. The day became warm, the sky soft and clear, as the soldiers approached Dranesville. About noon the flanking companies of the Twelfth regiment came in and reported that a large body of rebels could be seen from a neighboring hill. At another part of the line shots were exchanged between the hidden enemy and the Union flanking companies. Instantly a line of battle was formed, but no enemy appeared, and the firing ceased. The delay was that of a few minutes. The Union men were anxious, expectant, and enthusiastic. Suddenly a fire was opened upon our line from a wood or thicket nearly a mile distant. The enemy’s battery contained six guns, and was placed in a road skirting the wood, and sheltered by it. Their guns were of large calibre, and they fired shells. At first they passed over the column and exploded beyond. The rebel artillerymen discovered this, altered their range, and their shells fell short. In the mean time, Easton’s battery was brought into position on the side of an elevation in front of the Twelfth regiment, which was in line of battle. General Ord himself sighted the guns, and a sharp fire was opened upon the enemy.