1892-1896 - Washington Alexandria & Mount Vernon Electric Railway Co.
1896-1910 - Washington Alexandria & Mount Vernon Railway Co.
1910-1927 - Washington-Virginia Railway Co.
1927-1930 - Washington Alexandria & Mount Vernon Railway Co.
1921-1973 - Alexandria Barcroft & Washington Transit Co.
1921 - buses introduced
1932 - streetcars discontinued
Arlington
1891-1896 - Washington & Arlington Railway Co.
1896-1910 - Washington Arlington & Falls Church Railway Co.
1910-1927 - Washington-Virginia Railway Co.
1925 - buses introduced by separate company Washington Virginia & Maryland Coach Co.
1927-1936 - Arlington & Fairfax Electric Railway Co.
1932 - buses introduced by affiliated company Arlington & Fairfax Motor Transportation Co.
1936-1939 - Arlington & Fairfax Auto Railroad
1937 - streetcars discontinued
1937-1939 - operated auto railer combination vehicles
1932-1947 - Arlington & Fairfax Motor Transportation Co.
1925-1973 - Washington Virginia & Maryland Coach Co.
CURRENT TRANSIT SYSTEM (SINCE 1973)
Washington Metropolitan Area Transit Authority
COMMUTER RAIL SERVICE
Virginia Railway Express