ill afford to lose 10,000 troops which had been counted upon in forming my plan of campaign, but as there was no remedy. I would yield, and do the best I could without them. In a conversation with the President a few hours afterwards I repeated verbally the same thing, and expressed my regret that Blenker's division had been given to General Fremont from any pressure other than the requirements of the national exigency. I was partially relieved, however, by the President's positive and emphatic assurance that I might be confident that no more troops beyond these 10,000 should in any event be taken from me or in any way detached from my command.

At the time of the evacuation of Manassas by the enemy Jackson was at Winchester, our forces occupying Charlestown, and Shields' reaching Bunker Hill on the 11th. On the morning of the 12th a brigade of General Banks' troops, under General Hamilton, entered Winchester, the enemy having left at 5 o'clock the evening before, his rear guard of cavalry leaving an hour before our advance entered the place. The enemy having made his preparations for evacuation some days before, it was not possible to intercept his retreat. On the 13th the mass of Banks' corps was concentrated in the immediate vicinity of Winchester, the enemy being in the rear of Strasburg. On the 19th General Shields occupied Strasburg, driving the enemy 20 miles south to Mount Jackson. On the 20th the first division of Banks' corps commenced its movement towards Manassas, in compliance with my letter of instructions of the 16th. Jackson probably received information of this movement, and supposed that no force of any consequence was left in the vicinity of Winchester, and upon the falling back of Shields to that place, for the purpose of enticing Jackson in pursuit, the latter promptly followed, whereupon ensued a skirmish on the 22nd, in which General Shields was wounded, and an affair at Winchester on the 23rd, resulting in the defeat of Jackson, who was pursued as rapidly as the exhaustion of our troops and the difficulty of obtaining supplies permitted. It is presumed that the full reports of the battle of Winchester were forwarded direct to the War Department by General Banks.

It being now clear that the enemy had no intention of returning by the Manassas route, the following letter of April 1 was written to General Banks:

HEADQUARTERS ARMY OF THE POTOMAC,
On Board the Commodore, April 1, 1862.

GENERAL: The change in affairs in the valley of the Shenandoah has rendered necessary a corresponding departure, temporarily at least, from the plan we some days since agreed upon.

In my arrangements I assume that you have with you a force amply sufficient to drive Jackson before you, provided he is not re-enforced largely. I also assume that you may find it impossible to detach anything towards Manassas for some days, probably not until the operations of the main army have drawn all the rebel force towards Richmond.

You are aware that General Sumner has for some days been at Manassas Junction with two divisions of infantry, six batteries, and two regiments of cavalry, and that a reconnaissance to the Rappahannock forced the enemy to destroy the railway bridge at Rappahannock Station, on the Orange and Alexandria Railroad. Since that time our cavalry have found nothing on this side the Rappahannock in that direction, and it seems clear that we have no reason to fear any return of the rebels in that quarter. Their movements near Fredericksburg also indicate a final abandonment of that neighborhood. I doubt whether Johnston will now re-enforce Jackson with a view of offensive operations. The time is probably past when he could have gained anything by doing so. I have ordered in one of Sumner's divisions (that of Richardson, late Sumner's) to Alexandria for embarkation. Blenker's has been detached from the Army of the Potomac and ordered to report to General Fremont. Abercrombie is probably at Warrenton Junction to-day. Geary is at White Plains. Two regiments of cavalry have been ordered out and are now on the way to relieve the two regiments of Sumner.