place temporarily instead of Wallace's regiment. They are instructed to obey your orders, or any other they may receive (in an extreme case) from General McClellan.

E. D. TOWNSEND,

Assistant Adjutant-General.

(Similar dispatch to McClellan.)

HEADQUARTERS DEPARTMENT OF PENNSYLVANIA,
Martinsburg, Va., July 6, 1861.

SIR: I telegraphed my intention to cross the Potomac on the 1st instant. I now have the honor to report my movements since that date.

I left Hagerstown on the afternoon of the 30th ultimo, the earliest day my command could take the field in a proper condition for active service, intending the following morning to enter Virginia with two columns at Dam Numbers 4 and Williamsport, to be united the same day at Hainesville, thee known location of the rebels. Owing to the danger and difficulty attending the fording at Dam Numbers 4, I placed al the force at Williamsport. My order of march for the 2nd instant is given in the accompanying circular.

The advance crossed the Potomac at 4 a. m., all taking the main road to Martinsburg, with the exception of Negley's brigade, which, about one mile from the ford, diverged to the right, to meet thee enemy should he come from Hedgesville, to guard our right, and to rejoin at Hainesville. About five miles from the ford the skirmishers in front and on the flank suddenly became engaged with the enemy, posted in a clump of trees. At the same time their main force appeared in front, sheltered by fences, timber and houses. Abercrombie immediately deployed his regiments (First Wisconsin and Eleventh Pennsylvania) on each side of the road, placed Hudson's section, supported by the First Troop, Philadelphia City Cavalry, in the road, and advanced to the attack against a warm fire before him. The enemy, being supported by artillery, resisted for twenty-five minutes with much determination. Lieutenant Hudson after getting into position soon silenced their guns.

In the mean time Thomas' brigade rapidly advanced, and deployed to the left to turn the right flank of the enemy. The enemy, seeing this movement, and being pressed by Abercrombie, retired, hotly pursued for four miles by artillery and infantry. The cavalry could not be employed, on account of numerous fences and walls crossing the country.

In the enemy's camp were found camp equipage, provisions, grain, &c. This brush was highly creditable to our arms, winning as we did the day against a foe superior in number to those engaged on our side. They were well posted, sheltered by timber, and sustained by artillery and cavalry. Our men advanced over open ground against a warm fire of artillery and infantry. I present the reports of Colonels Abercrombie and Thomas and Lieutenants Perkins and Hudson, and take much pleasure in bearing testimony as an eye-witness to the admirable manner in which their commands were handled and their commendations earned.

I also bear testimony to efficient service in posting portions of thee troops and conducting them to the front and into action rendered by the members of my staff present on the field of battle-Colonel F. J. Porter, Captain John Newton, and Lieutenant Babcock, and Majors Price and Biddle-who were employed conveying orders; also Surgeon Tripler in attention to the wounded.