Opening Day for Metrorail. Five stations open on the Red Line.

Gallery Place opens. A court order delayed its opening for missing disability access.

Red Line extended to Dupont Circle.

Blue Line opens from National Airport to Stadium-Armory.

Red Line opens to Silver Spring, inaugurating the first service to Maryland.

Orange Line opens to New Carrollton.
All trains run from National Airport to New Carrollton, signed Orange heading toward New Carrollton and Blue heading towards National Airport.

Orange Line extended to Ballston.
Orange and Blue are now two separate services.

Blue Line extended to Addison Road.
Orange and Blue run a strange service pattern (see notes below for more discussion).

Red Line extended to Van Ness.

Yellow Line opens from National Airport to Gallery Place.

Yellow Line extended to Huntington.

Red Line extended to Grosvenor.

Red Line extended to Shady Grove.

Orange Line extended to Vienna.
Gallery Place renamed Gallery Pl-Chinatown.

Red Line extended to Wheaton.
Navy Memorial opens; Archives station renamed Archives-Navy Mem'l.

Segment to U Street-Cardozo opens.
Service runs as Yellow Line temporarily.

Blue Line extended to Van Dorn Street.

Green Line formally opens from U Street to Anacostia.

Northern Green Line segment opens from Fort Totten to Greenbelt.

Green Line Commuter Shortcut opens as 6-month experiment. Peak period Green Line trains use a switch to access the Red Line to Farragut North.
Ballston renamed Ballston-MU.

Blue Line extended to Franconia-Springfield. Green Line Commuter Shortcut continued, though it never appeared on official maps as it was always meant to be temporary.

Red Line extended to Glenmont. Waterfront renamed Waterfront-SEU.

Inner Green Line segment opens from U Street to Fort Totten, replacing Green Line Commuter Shortcut. Woodley Park, U Street, West Falls Church, Dunn Loring, and Vienna get additional elements added to their names.

Green Line extended to Branch Avenue.
The originally-planned system is now complete.
Addison Road renamed to Addison Road-Seat Pleasant.

New York Ave-Florida Ave/Gallaudet U infill station opens on the Red Line.
Mt. Vernon Sq., Rhode Island Ave., and National Airport get new names.

Blue Line extended to Largo Town Center.

Yellow Line begins running off-peak to Fort Totten.
Music Center at Strathmore opens; Grosvenor station renamed to Grosvenor-Strathmore.

"Rush Plus" adds new rush patterns on the Orange and Yellow Lines.
NoMa station gets new name; Ballpark and Old Town added to names; SEU removed.
11 stations with long names use new concept of subtitles.

Silver Line opens from Wiehle-Reston East to Largo Town Center with five new stations.

Rush Plus is eliminated. Foggy Bottom and Smithsonian get new subtitles.

Silver Line Phase 2, to Ashburn, is slated to open in 2020.