The Alexandria Extension is a short rail line in Washington, D.C. and Prince George's County, Maryland. Its northern portion connects the Capital Subdivision to the RF&P Subdivision, allowing freight trains to avoid Downtown Washington. Its southern portion, the Shepherd Industrial Spur (aka Shepherd Branch), extends south to Shepherds Landing, directly across the Potomac River from Alexandria, Virginia; service on this portion ended in 2001.
It is currently part of CSX Transportation's Capital Subdivision.[1]