Engage guides in sufficient numbers at once, and endeavor to send out spies.

I am very truly yours,

GEO. B. MCCLELLAN,

Maj.-Gen. Comd'g.

The remaining divisions embarked as rapidly as transports could be supplied.

On the 1st of April I embarked, with the head-quarters on the steamer Commodore, and reached Fort Monroe on the afternoon of the 2d.

In consequence of the delay in the arrival of the horse transports at Alexandria, but a small portion of the cavalry had arrived, and the artillery reserve had not yet completed its disembarkation.

I found there the 3d Pennsylvania Cavalry, and the 5th Regular Cavalry; the 2d Regular Cavalry and a portion of the 1st had arrived, but not disembarked: so few wagons had arrived that it was not possible to move Casey's division at all for several days, while the other divisions were obliged to move with scant supplies.

As to the force and position of the enemy, the information then in our possession was vague and untrustworthy. Much of it was obtained from the staff-officers of General Wool, and was simply to the effect that Yorktown was surrounded by a continuous line of earth-works, with strong water batteries on the York River, and garrisoned by not less than 15,000 troops, under the command of General J. B. Magruder. Maps which had been prepared by the Topographical Engineers under General Wool's command were furnished me, in which, the Warwick River was represented as flowing parallel to, but not crossing the road from Newport News to Williamsburg, making the so-called Mulberry Island a real island; and we had no information as to the true course of the Warwick across the Peninsula, nor of the formidable line of works which it covered.*

*The dotted line on the accompanying map shows the line of the Warwick River, as laid down on the maps referred to.

Information which I had collected during the winter placed General Magruder's command at from 15,000 to 20,000 men, independently of General Huger's force at Norfolk, estimated at about 15,000. It was also known that there were strong defensive works at or near Williamsburg.

Knowing that Gen. Huger could easily spare some troops to reinforce Yorktown, that he had indeed done so, and that Johnston's army of Manassas could be brought rapidly by the James and York rivers to the same point, I proceeded to invest that town without delay.

The accompanying map of Colonel Cram, United States Topographical Engineers, attached to General Wool's staff, given to me as the result of several months' labors, indicated the feasibility of the design. It was also an object of primary importance to reach the vicinity of Yorktown before the enemy was reinforced sufficiently to enable him to hold in force his works at Big Bethel, Howard's Bridge, Ship Point, etc., on the direct road to Yorktown, and Young's Mills on the road from Newport News. This was the more urgent as it was now evident that some days must elapse before the 1st Corps could arrive.

Every thing possible was done to hasten the disembarkation of the cavalry, artillery and wagons in the harbor, and on the 3d the orders of march were given for the following day.

There were at Fort Monroe and its vicinity, on the 3d, ready to move, two divisions of the 3d Corps, two divisions of the 4th Corps, one division of the 2d Corps, and Sykes's brigade of regular infantry, together with Hunt's artillery reserve, and the regiments of cavalry before named, in all about 58,000 men and 100 guns. Richardson's and Hooker's divisions of the 2d and 3d Corps had not yet arrived, and Casey's division of the 4th Corps was unable to move for want of wagons.

ANOTHER REDUCTION OF FORCE.

Before I left Washington an order had been issued by the War Department, placing Fort Monroe and its dependencies under my control, and authorizing me to draw from the troops

under General Wool, a division of about 10,000 men, which was to be assigned to the 1st Corps. During the night of the 3d I received a telegram from the adjutant-general of the army, stating that, by the President's order, I was deprived of all control over General Wool and the troops under his command, and forbidden to detach any of his troops without his sanction.

This order left me without any base of operations under my own control, and to this day I am ignorant of the causes which led to it.

CO-OPERATION OF THE NAVY.

On my arrival at Fort Monroe the James River was declared, by the naval authorities, closed to the operations of their vessels, by the combined influence of the enemy's batteries on its banks and the confederate steamers Merrimac, Yorktown, Jamestown, and Teazer. Flag-officer Goldsborough, then in command of the United States squadron in Hampton Roads, regarded it (and, no doubt, justly) as his highest and most imperative duty to watch and neutralize the Merrimac, and as he designed using his most powerful vessels in a contest with her, he did not feel able to detach, for the assistance of the army, a suitable force to attack the water batteries at Yorktown and Gloucester. All this was contrary to what had been previously stated to me, and materially affected my plans. At no time during the operations against Yorktown was the navy prepared to lend us any material assistance in its reduction, until after our land batteries had partially silenced the works.

ADVANCE FROM FORT MONROE.

I had hoped, let me say, by rapid movements, to drive before me or capture the enemy on the Peninsula, open the James River, and press on to Richmond before he should be materially reinforced from other portions of his territory. As the narrative proceeds, the causes will be developed which frustrated these apparently well-grounded expectations.