ains, within 1 1/2 miles of Leesburg, at 8 o'clock in the evening, without meeting with any further signs of his scouts or pickets. i here learned that a body of 1,200 of the enemy's cavalry, with two guns, were encamped at Snicker's Gap, and that 2,000 had left Leesburg that day for Aldie. Posting three squadrons of cavalry and three guns on the summit of the mountain, the main body at the intersection of the Waterford road with the Leesburg and Winchester turnpike, and thoroughly picketing in every direction, I rested for the night, the men sleeping on their arms.

At early dawn, the advance entered Leesburg, and found no enemy there except a number of sick and convalescent, who were taken prisoners and paroled. A list of their names* is hereto attached. At 9 o'clock the line of march was taken up, and, leaving Waterford on the right, I moved, on the road leading through Wheatlandand and Hillsborough into the valley between the Blue Ridge and Short Hills, to a point about 10 miles from harper's Ferry, where I went into camp at 3 p. m. Along this road their enemy's pickets were posted in several places, but they fled toward the mountains on our approach. In consequence of information brought in by my scouts early in the evening, relating to the roads leading toward and around the ground I occupied, and that contained in your dispatch, which reached me at 8.30 o'clock in the evening, I broke up camp and marched into Harper's Ferry that night, reaching the old camp-ground at 2 o'clock this morning, having marched 43 miles in the enemy's country in as many hours.

The Catoctin Valley, and the valley between the Blue Ridge and Short Mountains, in the vicinity of Hillsborough, contain an abundance of hay and large quantities of grain and cattle, and the inhabitants in the Catoctin Valley appear, generally, to be loyal.

I ascertained that a force of about 1,200 of the enemy's cavalry were encamped at the pass near Snickersville, and that, with the exception of occasionally a small squad in search of plunder and conscript, there was no enemy in the vicinity of Leesburg or in the Valley of Catoctin. Information was received that the main body of the rebel army was at Bunker Hill, half-way between Martinsburg and Winchester, and that a large force was at Kernstown, 3 1/2 miles south of the latter place.

I desire to express to you my admiration of the soldierly conduct of both officers and men of the Sixth U. S. Cavalry under the command of Captain Sanders, as well as that of Major Robertson, of the horse artillery, and Captain Frank, of the Second New York Artillery, as exhibited in the thorough and earnest performance of their arduous duties in an exceedingly rough and difficult country; and, although meeting no enemy, their was such as to inspire me with confidence in their skill and bravery.

My old command fully sustained its reputation for fortitude and endurance. Many of them, in a most commendable spirit left camp, for this march who were not physically able to endure it, as the day was very hot, the country, and the march very fatiguing and some of these fell out, from sheer exhaustion, and returned slowly to camp; but the motive that actuated them is an honor. General, I am proud of my brigade.

I have the honor to be, sir, very respectfully, your obedient servant,

NATHAN KIMBALL,

Brigadier-General, Commanding.

Lieutenant Colonel J. H. TAYLOR,

Chief of Staff and Assistant Adjutant-General.

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*Omitted.

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