Numbers 6. Report of Brigadier General Silas Casey, U. S. Army, commanding Provisional Division.

HEADQUARTERS PROVISIONAL BRIGADES,
568 14th Street, Washington, D. C., December 31, 1862.

SIR: I have the honor to inclose General Stoughton's and Colonel D'Utassy's reports of their movements during the rebel raid of the 28th instant. General Stoughton accomplished all that could be done without cavalry, and I am well satisfied with Colonel D'Utassy's operations with his slender brigade.

In my opinion, two regiments of cavalry placed at the disposal of General Stoughton in time would have been able to cut off many of the enemy and to have driven off the rest.

Immediately on receipt of information that the enemy had crossed the Occoquan, my pickets south of Hunting Creek were strengthened and my troops in that position kept on the alert. In my opinion, the enemy intended an attack on Fairfax Station, and my orders to General Stoughton and Colonel D'Utassy were to hold that position at all hazards.

Very respectfully, your obedient servant,

SILAS CASEY,

Brigadier-General of Vols., Commanding Div. and Provisional Brigades.

Captain C. H. POTTER,

Asst. Adjt. General, Hdqrs. Defenses of Washington.

Numbers 7. Report of Colonel Frederick G. D'Utassy, Thirty-ninth New York Infantry, commanding First Brigade.

HDQRS. FIRST BRIGADE, PROVISIONAL DIVISION,
Union Mills, Va., December 30, 1862.

SIR: I beg to report that on Sunday, December 28, at 4.50 p.m., a mounted messenger of the First Michigan Cavalry, coming from Woodyard's Ford, the Occoquan, seemingly intending to attack Fairfax Station, and to capture or destroy the stores there. Later news reached me that they were cavalry and artillery, and still later that the former were from 1,500 to 3,000 horses in number and the latter six pieces.

I immediately strengthened my picket line in front and threw out patrols in the direction of Blackburn's Ford to Centreville, to secure my right flank, and ordered Colonel Wyndham, commanding a cavalry brigade, who accidentally was, with about 400 cavalry, at my post, to march to Fairview, take post there, and throw out to the front as far as Brimstone Hill a cavalry detachment to patrol the roads leading from across the Bull Run and Occoquan River to that place, and patrol the country in semicircle from Burke's Station to Sangester's Station. For the purpose of strengthening him, I detailed four companies of infantry and a section of artillery, to be under his orders at Fairview; also eight companies, to take post at the fork of roads formed by the one leading from Union Mills to Woodyard's Ford and Wolf Run Shoals, which detachment should communicate with the extreme left of my line of pickets at Woodyard's Ford. Thus my left flank was secured, and Fairfax Station covered by it in the same direction.