force must be taken for guards, scouts,&c. With this army I could assault the enemy's works, and perhaps them, but were I in possession of their intrenchments and assailed by double my number I should have no fears as to the result.

Under the circumstances that have bene developed since we arrived here I feel fully impressed with the conviction that there is to be fought the great battle that is to decide the existing contest. I shall of course commence the attack as soon as I can get up my siege train, and shall do all in my power to carry the enemy's works; but to do this with a reasonable degree of certainty requires, in my judgment, that I should, if possible, have at least the whole of the First Corps to land upon the Severn River, and attack Gloucester in the rear. My present strength will not admit of a detachment sufficient for this purpose without materially impairing the efficiency of this column. Flag-Officer Goldsborough thinks the works too strong for his available vessels unless I can turn Glucester.

I send by mail copies of his letter and one of the commander of hate gunboats here.

GEO. B. McCLELLAN,

Major-General.

Hon. E. M. STANTON, Secretary of War.

I had provided a small siege train and moderate supplies of intrenching tools for such a contingency as the present. Immediate steps were taken to secure the necessary additions. While the engineer officers were engaged in ascertaining the character and strength of all the defenses and the configuration of the ground in for of Yorktown in order to determine the point of attack and to develop the approaches, the troops were occupied in opening roads to the depots established at the nearest available points on branches of York River. Troops were brought to the front as rapidly as possible, and on the 10th of April the army was posted as follows:

Heintzelman's corps, composed of Porter's, Hooker's and Hamilton's divisions, in front of Yorktown, extending in the order named from the mouth of Wormerly's Creek to the Warwick road opposite Wynn's Mill; Sumner's corps - Sedgwick's division only having arrived-on the left of Hamilton, extending down to Warwick and opposite to Wynn's Mill works; Keyes' corps (Smith's, Couch's, and Casye's division), on the left of Sedgwick, facing the works at the one-gun battery, Lee's Mill,&c., on the west bank of the Warwick.

Sumner, after the 6th of April, commanded the left wing, composed of his own and Keyes' corps.

Throughout the preparations for and during the siege of Yorktown I kept the corps under General Keyes, and afterward the left wing, under General Sumner, engaged in ascertaining the character of the obstacles present by the Warwick, and the enemy intrenched on the right bank, with the intention, if possible, of overcoming them and breaking that line of defense, so as to gain possession of the road to Williamsburg and cut off Yorktown from its supports and supplies. The forces under General Heintzelman were engaged in similar efforts upon the works between Wynn's Mill and Yorktown. General Keyes' report of the 16th of April, inclosing reports of brigade commanders engaged in reconnaissance up to that day, said "that no part of his (the enemy's line opposite his own) line, so far as discovered, can be taken by assault without an enormous waste of life."

Reconnaissance on the right flank demonstrated the fact that the Warwick was not passable in that direction except over a narrow dam, the approaches to which were swept by several batteries an intrenchments, which could be filled quickly with supports sheltered by the timber immediately in rear.

General Barnard, chief engineer of the Army of the Potomac, whose position entitled his opinions to the highest consideration, expressed the judgment that those formidable works could not with any reasonable degree of certainty be carried by assault. General Keyes,