HEADQUARTERS TWENTIETH ARMY CORPS, Near Alpine, September 13, 1863-8.30 a. m.

Brigadier General J. A. GARFIELD,
Chief of Staff:

Your communication dated the 12th (without stating the hour) reached me at 12.30 o'clock last night. My movement commenced at daylight this morning. I am marching on Dougherty's Gap, at the head of McLemore's Cove. This road is a short distance above Stevens' Gap, and about 7 miles above the Blue Bird Gap, and 9 miles above Dug Gap of the Pigeon Mountain, leading over to La Fayette. I will be with General Thomas to-night, or very near him. I have had no positive information from the cavalry.

General Crook encamped about 10 miles from this place toward La Fayette last night, and thinks the enemy have evacuated La Fayette with their infantry. Immense clouds of dust were seen all day yesterday in the direction of that place. I have assumed no control over the cavalry, but suggested that General Crook be required to drive in the enemy's infantry pickets at La Fayette if they are there. If I hear any further from the cavalry, I will express it to you.

I saw a letter to General Stanley, written by Major Bond, in which I am charged of being guilty of offense-classified by the general commanding as the next worst thing to running from the enemy. I have always had a courier line between my headquarters and department headquarters, with the exception of a few hours, since I left Will's Valley, therefore Major Bond's charges are without foundation. The headquarters of the department were moved away from Stevenson to Trenton without my knowledge. They were moved from Trenton to Chattanooga without my knowledge. I cannot be responsible for the courier line of the Anderson Cavalry. It took them nine hours to convey and order to me a distance of 20 1/2 miles. In another instance it took them from 7 p. m. till 3 a. m. to convey a dispatch from me to General Sheridan, a distance of 7 miles (dispatch marked gallop). Such conduct as this explains the delay in communicating with department headquarters.

Very respectfully,

A. McD. McCOOK,

Major-General, Commanding.

HEADQUARTERS TWENTIETH ARMY CORPS, Near Alpine, September 13, 1863-11.30 a. m.

Brigadier General J. A. GARFIELD,
Chief of Staff:

My ammunition trains are now nearly all up the mountain. My troops will commence the ascent in a few moments. I will push on as far as I can, but am afraid darkness will overtake me before I reach Dougherty's Gap. I have had but one communication from General Thomas and know nothing of his position, and do not know whether the enemy has possession of the head of McLemore's Cove or not. I hope to know in a short time. Your orders last night in regard to trains will be strictly complied with. General Stanley is quite ill and has to be transported. He has heard nothing from his cavalry this morning.

Lieutenant Thomas, of First [Third] Kentucky Cavalry (rebel), was