Telegram To General G. B. Mcclellan.

[Sent In Cipher.]

War Department, Washington City, D. C., May 25,1862. 8.30 P.M.

MAJOR-GENERAL McCLELLAN:

Your despatch received. General Banks was at Strasburg, with about 6,000 men, Shields having been taken from him to swell a column for McDowell to aid you at Richmond, and the rest of his force scattered at various places. On the 23d a rebel force of 7000 to 10,000 fell upon one regiment and two companies guarding the bridge at Front Royal, destroying it entirely; crossed the Shenandoah, and on the 24th (yesterday) pushed to get north of Banks, on the road to Winchester. Banks ran a race with them, beating them into Winchester yesterday evening. This morning a battle ensued between the two forces, in which Banks was beaten back into full retreat toward Martinsburg, and probably is broken up into a total rout. Geary, on the Manassas Gap railroad, just now reports that Jackson is now near Front Royal, With 10,000, following up and supporting, as I understand, the forces now pursuing Banks, also that another force of 10,000 is near Orleans, following on in the same direction. Stripped here, as we are here, it will be all we can do to prevent them crossing the Potomac at Harper's Ferry or above. We have about 20,000 of McDowell's force moving back to the vicinity of Front Royal, and General Fremont, who was at Franklin, is moving to Harrisonburg; both these movements intended to get in the enemy's rear.

One more of McDowell's brigades is ordered through here to Harper's Ferry; the rest of his force remains for the present at Fredericksburg. We are sending such regiments and dribs from here and Baltimore as we can spare to Harper's Ferry, supplying their places in some sort by calling in militia from the adjacent States. We also have eighteen cannon on the road to Harper's Ferry, of which arm there is not a single one yet at that point. This is now our situation.

If McDowell's force was now beyond our reach, we should be utterly helpless. Apprehension of something like this, and no unwillingness to sustain you, has always been my reason for withholding McDowell's force from you. Please understand this, and do the best you can with the force you have.

A. LINCOLN.