OR, Series 1, Vol. 2, Page 866

Headquarters Virginia Forces
Richmond, Va., May 22, 1861
Col. George H. Terrett, Commanding, etc., Alexandria, Va.
  Unless you can devise some better plan for securing the rolling stock of the Loudoun and Hampshire {Alexandria, Loudoun & Hampshire} Railroad than that suggested to you in my letter of the 19th instant, I desire you to adopt it, and give directions that a track be laid from the depot of the Loudoun and Hampshire Railroad to the Orange & Alexandria Railroad, in Union street, or some other more convenient point, by which this rolling stock can be carried to a place of safety on the Orange & Alexandria Railroad when not wanted for use on its proper road, and confer with presidents and directors of said roads as to perfecting this connection, which will not only be useful for the above purpose, but afford convenient transportation from one road to the other.
Very respectfully, etc.
R. E. Lee
Major-General, Commanding