National Railroad Passenger Corporation (Amtrak) Geographic map of the Amtrak system Reporting mark AMTK, AMTZ Locale Contiguous United States (except Wyoming and South Dakota) Ontario, British Columbia, and Quebec in Canada Dates of operation May 1, 1971–present Predecessor 20 privately operated intercity passenger rail systems Track gauge 4 ft 8 1⁄2 in (1,435 mm) standard gauge Electrification 12 kV, 25 Hz AC Northeast Corridor (Washington, D.C. – New Haven) Philadelphia to Harrisburg Main Line (Keystone Corridor) 25 kV, 60 Hz AC Northeast Corridor (New Haven – Boston) Length 44 routes: 21,300 miles (34,000 km) Track owned: 730 miles (1,170 km) Headquarters Union Station, Washington, D.C. Website www.amtrak.com