In accordance with this order, I left camp on the morning of the 17th instant, and proceeded with my regiment(275 strong) to Thoroughfare Gap. At this place my skirmishers met and engaged the enemy, which proved to be Lee's brigade of cavalry approaching the Gap. The enemy being much stronger than my command, I was obliged to make a demonstration on my left flank in order to pass my column unseen. At this demonstration the enemy retired, and I was enabled to pass my column on to the Middleburg road safety. Nevertheless they followed in my rear, but at a considerable distance, causing me no uneasiness. It was then 9. 30 a, m., and at 11 o'clock their skirmishers disappeared, and I proceeded unmolested toward Middleburg, using a negro for a guide. Arriving near Middleburg at 4 p. m., I again engaged the enemy, capturing his first picked in the road, and ordered Captain Allen, commanding the advanced squadron, to charge through the town. By this movement the rear guard of General Stuart was cut off, and then a sharp cavalry fight ensued between, his rear my advance guard. This engagement lasted half an hour, when the enemy was compelled to retreat in the greatest disorder and confusion, scattering in all direction. Having received information that Stuart, with 2, 000 cavalry and four pieces of artillery, had left town but half an hour before my arrival, and was proceeding to Aldie, I directed that the different roads leading into the town be barricaded and strongly picketed, and gave instructions to the officer commanding the outposts to hold the town at all hazards, hoping that after effecting communication with General Kilpatrick, whom I supposed to be at Aldie, I should receive r-enforcement. Captain Allen was selected to carry a dispatch to General Kilpatrick, and was directed to avoid as much as possible all main roads. The town was held by my command from 4. 30 to 7 p. m., the skirmishers having been constantly engaged during that time. At 7 o'clock I ascertained that the enemy was approaching in force from Aldie, Union, and Upperville. Determined to hold the position if possible, I dismounted one-half of my regiment, placing them behind stone walls and the barricades. The enemy surrounded the town and stormed the barricades, but were gallantly repulsed by my men with great slaughter. They did not however, desists, but, confident of success, again attacked, and made three successive charges. I was compelled to retire on the road by which I came, that being the only one open to retreat. With all that was left of my command, I crossed Little River northeast of Middleburg, and bivouacked for the night, establishing strong pickets on the river. In this engagement I lost Major Farringhton, Captains Rogers, Wyman, and Chase. Lieutenant Brown, and 27 men killed, wounded, and missing. At 10 p. m., having heard nothing from my dispatch sent to General Kilpatrick, I sent 20 men, under an officer, with a second dispatch. I have heard nothing from either party, and believe that both have been captured. At 3. 30 o'clock the nest morning, 18th instant, I was informed by scouts whom I had previously sent out that the roads in every direction were full of cavalry, and that the Aldie road was commanded by brigade, with four pieces of artillery. Under these circumstances by a brigade, with four pieces of artillery. Under these circumstances by a brigade, with four pieces of artillery. Under these circumstances I abandoned the project of going to Union, but determined not to surrender in any event. I directed the head of my column of the road to Aldie, when an engagement commenced at once, the enemy opening