The Baltimore and Ohio Short Line Railroad was the successor to the Pittsburgh Southern Railway, and a subsidiary of the B&O Railroad, and was organized as a legal entity 25 February 1885. The railroad was a link in the attempt of the B&O to serve the Pittsburgh market, and became part of the Wheeling Division of that railroad. It was constructed by gauge conversion of the former narrow gauge railway to and the building of the Whitehall Tunnel. It ran from Glenwood Junction to Washington, Pennsylvania, a distance of 34 miles.