positively on their return. Some contraband now in my camp passed fifteen or sixteen loads of sick on the road to-day. Another contraband is in from Centreville, who tells me that the enemy in and around Manassas retreated to Gordonsville. This was talked of all over the rebel camp. The portion of the army immediately on the Potomac left to take post at Fredericksburg. This I learn from some contraband and white people-from the former every hour in the day. Of these, Whiting's Archer's, and Rodes' brigades number about 12,000; the garrison in Fredericksburg about 3,000, and the force of Aquia and Potomac Creeks about 2,000, which will give the force in or near Fredericksburg 17,000. If they have been re-enforced from the Manassas army, it is that much greater. I have two companies in Dumfries to-night for the purpose of collecting information. It is reported to me that Hampton's Legion, stationed at Occoquan, fell back on Manassas.

JOSEPH HOOKER,

Brigadier-General.

BUDD'S FERRY, March 12, 1862.

Brigadier General R. B. MARCY:

Have received your dispatch of to-day. Shall proceed to execute to the best of my ability. From my most reliable information I can learn of but two companies of cavalry nearer me than the center of Stafford County. The report among the citizens of Prince William County is that the rebels have retired, to make the Rappahannock their line of defense. Too much faith should not be put in this. The pickets remain at Aquia Creek. The cars were running all night from that depot.

JOSEPH HOOKER,

Brigadier-General.

HEADQUARTERS DEPARTMENT OF WESTERN VIRGINIA, Wheeling, March 12, 1862.

Brigadier General L. THOMAS,
Adjutant-General U. S. Army, Washington, D. C.:

GENERAL: The General-in-Chief directed me to examine into the advantages of the Big Sandy route from the Ohio River to the Southwestern and Tennessee Railroad. He also directs me to cause the troops and material thrown into this department by General Orders, Numbers --, headquarters of the Army, to be thoroughly inspected, and to report their condition, and also what troops I wanted; and, if so, what, if any more, cavalry. These considerations involving that of the operations advisable to be undertaken within the department, I have thought it better to present the whole matter in a report, which I have the honor herewith to inclose.

Very respectfully, your obedient servant,

W. S. ROSECRANS,

Brigadier-General, U. S. Army.

[Inclosure.]

HEADQUARTERS DEPARTMENT OF WESTERN VIRGINIA, Wheeling, March 12, 1862.

Brigadier General L. THOMAS,

Adjutant-General U. S. Army, Washington, D. C.:

GENERAL: Since the valley of Virginia, except the valleys of Great and Little Cacapon and of the Shenandoah, had been added to the limits