Streetcars and interurbans operated in the Maryland suburbs of Washington, D.C., between 1890 and 1962. Lines in Maryland were established as separate legal entities, but eventually they were all owned or leased by DC Transit. Unlike the Virginia lines the Washington and Maryland lines were scheduled as a single system. Most of the streetcars were built with grand plans in mind, but none succeeded financially. A combination of the rise of the automobile, various economic downturns and bustitution eventually spelled the end of streetcars in southern Maryland.

The City and Suburban Railway was chartered in 1890 to run a streetcar from just east of the White House at New York Ave and 15th St NW to what is now Mount Rainier on the D.C. line. On March 31st, 1892 the Maryland and Washington Railway incorporated to build a rail line connecting any passenger railway in the District of Colmbia to Branchville and eventually Laurel