The line ran under the designation X42, with X being used as a prefix for the Third Avenue Railway's crosstown routes.

[2] The M42 utilizes the same route as the streetcar, except that it loops around on its eastern end using the FDR Drive, 41st Street and First Avenue.

Originally chartered in 1878, the Forty-Second Street, Manhattanville & St. Nicholas Railway started service with horsedrawn carriages in 1884, with the Third Avenue Railway acquiring the line in 1896, and alongside it, the streetcar line.

[citation needed] On November 17, 1946, the streetcar line was replaced by the Surface Transportation Corporation's, the bus-operating subsidiary of the Third Avenue Railway, M106 bus route.

[6] On June 27, 2010, due to a budget crisis, service on the Javits Center branch was discontinued.