OR, Series 1, Vol. 2, Page 858

Headquarters Virginia Forces
Richmond, Va., May 19, 1861
Lieut. Col. George H. Terrett
Commanding at Alexandria, Va.
  Major-General Lee instructs me to acknowledge the receipt of your letter of May 16. It is very important to secure the rolling stock of the Loudoun and Hampshire {Alexandria, Loudoun & Hampshire} Railroad, but General Lee thinks it would be quite as much exposed to seizure by the enemy at any point on that road near Alexandria as in the town itself. If taken up that road for safety, it should be taken to Leesburg or its vicinity. General Lee thinks it would be better (if practicable) to obtain the cooperation of the Alexandria, Loudoun & Hampshire and the Alexandria and Orange {Orange & Alexandria} Railroad Companies in the construction of a temporary track connecting the two roads, to run the cars of the Loudoun and Hampshire Road out on the track of the Orange & Alexandria Road at night, as a precautionary measure.
I am, etc.
Jno. A. Washington