HAGERSTOWN, July 7, 1863.

Mr. PRESIDENT: My letter of the 4th instant will have informed you of the unsuccessful issue of our final attack on the enemy in the rear of Gettysburg . Finding the position too strong to be carried, and, being much hindered in collecting necessary supplies for the army, by the numerous bodies of local and other troops which watched the passers, I determined to withdraw to the west side of the mountains . This has been safely accomplished with great labor, and the army is now in the vicinity of this place . One of my reason for moving in this direction, after crossing the mountains, was to protect our trains with the sick and wounded, which had been sent back to Williamsport, and which were threatened by the enemy's cavalry . Our advance reached here yesterday afternoon in time to support our cavalry in repulsing an attempt of the enemy to reach our trains . Before leaving Gettysburg, such of the sick and wounded as could be removed were sent back to Williamsport, but the trains that have interfered so much with our general movements have so swollen the Potomac as to render it unfordable, and they are still on the north side. Arrangements are being made to ferry them across to- day. We captured at Gettysburg about 6, 000 prisoners, besides the wounded that remained in our hands after the engagements of the 1st and 2d. Fifteen hundred of these prisoners and the wounded were paroled, bud I suppose that under the late arrangements these paroles will not be regarded. The rest have been sent to Williamsport, where they will cross. We were obliged to leave a large number of our wounded who were unable to travel, and many arms that had been collected on the field at Gettysburg. In addition to the general officers killed or wounded, of whom I sent you a list in my former letter, I have to mention General Semmes, General G. T. Anderson, Pettigrew, and General J. M. Jones, wounded; General Archer was made prisoner. General Heth is again in command. In sending back our trains in advance, that of General Ewell was cut the enemy's cavalry, and a number of wagon, said to be about 40 were captured. The enemy's cavalry force, which attempt to reach our cavalry trains yesterday afternoon, was a large one. They came as far as Hagerstown, where they were attacked by General Stuart, and driven back rapidly toward Sharpsburg. Very respectfully, your obedient servant,

R. E. LEE,

General.

His Excellency JEFFERSON DAVIS,

President Confederate States

- HEADQUARTERS ARMY OF NORTHERN VIRGINIA, Near Hagerstown, Md., July 8, 1863.

MR PRESIDENT: My letter of yesterday will have informed you of the position of this army. Though reduced in numbers by the hardships and battles `trough which it has passed since leaving the Rappahannock, its condition is good, and its confidence unimpaired. Upon crossing the Potomac into Maryland, I had calculated upon the river remaining fordable during the summer, so as to enable me to recross at my pleasure, but a series of storms, commencing the day after our entrance into Maryland, has placed the river beyond