In view of the delay in the cavalry movement, the order directing it is revoked, and consequently your last instructions in regard to your supporting it.

The general is in some doubt as to the direction General Crook is to take, and directs that the brigade commanders ordered to support him communicate with him immediately, ascertain the route, and act upon the information, carrying [out] the above instructions according to his best judgment. In addition to the above, you are directed to send one brigade of cavalry, which is ordered to move on Alpine, and reconnoiter the Broomtown Valley to Alpine, and from there as far toward Summerville as may be safe and useful.

Your infantry support need not proceed farther than the foot of the Lookout Mountain toward Alpine. A thorough reconnaissance must be made, and the movements of the enemy ascertained, and it is necessary that no time should be lost in making it.

General McCook directs that you hold the remainder of your command in readiness for a forward movement. He wishes you to be certain to hold the gap or pass at Winston's, up on to the mountain, as well as to watch the roads at the top of the mountain leading from the main Alpine road.

I have the honor to be, general, most respectfully, your obedient servant,

G. P. THRUSTON,

Assistant Adjutant-General and Chief of Staff.

HEADQUARTERS TWENTIETH ARMY CORPS, Long's Spring, Ala., September 9, 1863-8.15 p.m.

Colonel P. SIDNEY POST,
Commanding First Brigade, First Division:

COLONEL: The enemy are reported to have evacuated Chattanooga and to be moving southward. Our corps is ordered in pursuit. General McCook directs that 3 a.m. to-morrow you have two-thirds of General Davis' ammunition train and the artillery of the Second and Third Brigades (left behind) moved on to the mountain, so as to get them toward the advance troops and out of the way of the two division in the rear. The general wishes you to send one of your strongest regiments up with them.

General Johnson's division will move up the mountain soon after daybreak, so that the artillery and ammunition train must be turned of the road so that his troops can pass. He has orders to take both the train and artillery along with his division to the advance brigades. General Johnson will leave at Winston's his baggage and supply trains, with a strong escort, and push on with his troops. By noon to-morrow General Sheridan's division will pass Winston's He also will leave his baggage and supply wagons there under an escort.

As soon as all the troops of the corps have passed up the mountain General McCook directs that you (with your brigade and the escorts left with the trains) perform the onerous and important duty of moving all the trains of the corps and the cavalry to the front, and bringing up the rear. The transportation, convalescents, &c., belonging to General Stanley's command will be ordered to the neighborhood of Winston's early to-morrow. Pack the transporta-