National Capital Region consists of the District of Columbia and the surrounding counties and independent cities in Maryland and Virginia as defined by the federal administrative guidelines used by agencies such as General Services Administration, the Department of Defense, and Homeland Security. Maryland counties that are included in the National Capital Region are Montgomery and Prince Georges; Virginia counties and independent cities include the City of Alexandria, Arlington County, the City of Falls Church, the City of Fairfax, Fairfax County, Loudoun County, the City of Manassas, the City of Manassas Park, and Prince William County.
