WASHINGTON, D. C, February 1, 1864-12. 30 p. m.

Major-General SEDGWICK, Army of the Potomac:

It is the opinion of General Kelley that Early is advancing on West Virginia and the Baltimore and Ohio Railroad with a large force, detached from Lee's army.

H. W. HALLECK,

General-in-Chief.

HEADQUARTERS ARMY OF THE POTOMAC, February 1, 1864-7. 30 p. m.

(Received 8. 30 p. m.)

Major General H. W. HALLECK, General-in-Chief.

The information collected here was that Thomas' brigade of Wilcox's division and Walker's brigade of Heth's division were the only infantry in the Shenandoah Valley, and they were in the upper valley; that Rosser's, part of Wickham's, and part of Lee's brigades of cavalry were also in the valley. It was known that these troops did not return to Lee's army after leaving it in December, but remained in the Shenandoah Valley to prevent raids and to collect animals, provisions, and forage from the Shenandoah and other valleys accessible to them,such as the valley of the South Branch of the Potomac, &c. No other from Lee's army is in the valley Imboden's force is believed to be there, but Jenkins is reported to be with Jones.

Two citizens arrested on the 31st of January (yesterday), upon entering our on the Sperryville road left the vicinity of Charlestown, near Harper's Ferry, on January 28. They passed through Middletown and Front Royal on the 29th, at which time they neither saw nor heard anything of the forces of the enemy, except of some cavalry at Harrisonburg. The movement of a force at this season from this army to the upper Shenandoah strong enough to attack and drive out the enemy would be costly to this army in men and animals. It is recommended as a preferable mode of securing the Baltimore and Ohio Railroad that General Kelley be re-enforced from this army,if he requires re-enforcements, by troops sent by railroad through Washington. Positive intelligence from the Shenandoah Valley will be received here early to-morrow morning.

JOHN SEDGWICK,
Major-General, Commanding.

HDQRS. ARMY OF THE POTOMAC, February 1, 1864.

Major-General BIRNEY, Commanding Third Corps:

The following dispatch from General Kilpatrick is respectfully referred to you for report, by direction of the major-general commanding:

Lieutenant Colonel C. ROSS SMITH,

Chief of Staff, Cavalry Corps:

My pass is still refused at the picket-lines on the main roads to Morton's and Germanna Fords. I can neither send to nor hear from my two main reserves since yesterday morning. This has been the cause.

J. KILPATRICK,

Brigadier-General.

A. A. HUMPHREYS,

Major-General, Chief of Staff.