Scammon, I retired to the top of Flat Mountain, and, finding that the enemy did not follow me with his main body, and was endeavoring to pass in my rear with a large cavalry force, I continued the retreat to this place, where I learned that the enemy's cavalry had passed through Abb's Valley, in Tazewell County. I at once sent some cavalry to intercept them, and some infantry to obstruct the roads. When they arrived in Tazewell, the enemy had gone in the direction of Wytheville. The cavalry pursued them until they met with Colonel [A. J.] May, of Brigadier-General Williams' command, who presumed to give them orders. &c., so that they accomplished but little, owing to the interference of those named above. On the morning of the 19th, I moved with a part of my infantry, cavalry, and artillery through Rock Gap in the direction of Wyntheville. I halted the infantry and artillery at the Gap, and went on with the cavalry, but, on reaching Bland Court-House, I found that the enemy had retired, and had gone back toward Tazewell County, coming at no time in my direction, or passing the mountain at any of the crossings by my forces. They passed beyond me, and as soon as I found I could never come up with them, I stopped at Rock Gap, and remained there. On the morning of the 19th, I also sent a sufficient garrison to the Narrows. I am sure that some one is to blame for the escape of the enemy. I am also of the opinion that the cavalry force that was in Tazewell, under General Williams and Colonel May, was sufficient to have captured the enemy, if it had been properly managed. Your attention is called to the report of Captain H. Bowen, Eighth Virginia Cavalry, herewith submitted, by which it appears that if the gap at Crabtree's had been occupied by Colonel May, or had he permitted Captain Bowen to have occupied it (which he would have done), the enemy would have been driven upon me at Rock Gap, and they could not have escaped. Again, if General Williams had moved with the celerity that the occasion required, and attacked the enemy in force, instead of skirmishing with his rear, he would have defeated them, and taken or scattered the most of them. I never could come up with them with my infantry, and those commanding the cavalry failed because they did not charge the enemy with their whole force when they did overtake them.

I have the honor to remain, your obedient servant,

JOHN MCCAUSLAND,

Colonel, &c.

Major C. S. STRINGFELLOW,

Assistant Adjutant-General.

No. 8. Report of Captain H. Bowen, Eighth Virginia Cavalry.

PRINCETON, VA., July 30, 1863.

SIR: In obedience to orders received from your headquarters, I left Princeton with a detachment of the Eighth Virginia Cavalry on the 18th instant, for Abb's Valley. I arrived at the Tug road about 10 p. m., and., finding that the enemy had gone toward Tazewell Court-House, I at once dispatched to you (Colonel McCausland), and resumed the march until I came within 2 miles of Tazewell Court-House, where I was compelled to graze my horses. As soon as possible, I moved toward Wytheville.