The Third Corps was encamped that night at Greenwich. The next morning I was ordered with my brigade and Captain McKnight's battery (N. Y.) to cover, as a rear-guard, the retreat of the Third Corps to Manassas Heights _via_ Bristoe Station. My orders were to avoid anything like a general engagement, but to beat back the advancing enemy whenever possible, prevent captures, and baffle him in his endeavors to delay or reach the main column. The successful conduct of a rear-guard of a retreating army, when pursued by an energetic foe, requires not only bravery but skill and tact. After the main body of my corps had left camp on its march towards Bristoe, and soon after daylight, the head of Lieutenant-General A. P. Hill's corps appeared from the direction of Warrenton. I displayed my troops with as much show of strength as possible, and with a few shots from the battery forced the enemy to halt his head of column and form line of battle. I thereupon retired by column quickly, and resumed the march until the enemy again pushed forward by the flank too near for my safety, when, in a chosen position, my troops were again speedily brought into line and a fire opened, which necessarily compelled him to halt and again make disposition for battle. This movement was frequently repeated. At each such halt the enemy necessarily consumed much time, thus giving the main body of the corps ample opportunity to proceed leisurely towards its destination. The weak or broken-down men of the rear-guard were not required to halt and fight, but were allowed to make such speed as they could. The day was almost spent when a courier reached me from French with the information that the corps had passed Bristoe Station, and was on the north side of Broad Run. Having now no further responsibility than for the safety of my own command, I moved more rapidly, and by 4 P.M. I had safely passed Bristoe Station to the high ground north of Broad Run, from whence I could, from a distance of less than a mile, see Bristoe, and, for a considerable distance, the line of railroad running, in general direction, north and south. The Third Corps had moved on out of sight towards the heights at Manassas. My command was much wearied, and I halted it for a short rest, but I soon ordered it forward where it took position in obedience to an order of General Meade to cover a blind road over which he feared the enemy might march to seize the heights. General A. P. Hill, in his report of the day, says: