Hampton's division, three brigades of cavalry, was concentrated last night, and moved across Stony Creek and by the shortest roads to Coggins' Point. This is the force that broke through our cavalry picket-line between Mount Sinai Church and Sycamore Church, and captured now on its return to Stony Creek.

A. A. HUMPHREYS,

Major-General and Chief of Staff.

HEADQUARTERS ARMY OF THE POTOMAC, September 16, 1864-8.30 a.m.

Colonel SMYTH,
Commanding Second Division, Second Corps:

The commanding general directs that you send a strong brigade immediately to report to General Kautz, near Prince George Court-House, and hold the remainder of your division ready to move at once in the same direction. Use dispatch, as the enemy's cavalry are there in some force, with artillery.

A. A. HUMPHREYS,

Major-General and Chief of Staff.

HEADQUARTERS ARMY OF THE POTOMAC, September 16, 1864-8.30 a.m.

(Received 9 a.m.)

Major-General HANCOCK,
Commanding Second Corps:

The enemy's cavalry have attacked in considerable force our cavalry line between the Blackwater and James, and successfully. Colonel Smyth, commanding Second Division, of your corps, is ordered to send a brigade at once to General Kautz, near Prince George Court-House, and to hold the remainder of his division ready to move in that direction. The order was sent to him direct to save time.

A. A. HUMPHREYS,

Major-General and Chief of Staff.

HEADQUARTERS SECOND ARMY CORPS, September 1, 1864.

General HUMPHREYS;

Dispatch received. I understood that Colonel Smyth has sent the brigade. I sent a staff officer to ascertain and to see that the brigade gets on the right road.

WINF'D S. HANCOCK,
Major-General.

HEADQUARTERS SECOND ARMY CORPS, September 16, 1864-9 a.m.

Major-General HUMPHREYS,

Chief of Staff, Army of the Potomac:

Nothing of importance has transpired on my line since yesterday morning to report. The usual picket-firing has been kept up. Some