Construction on Route 11B1, the section of the extension between 43rd Street and 61st Street, which includes the 59th Street station, began on March 15, 1913. Originally, this section was planned to have two tracks, but after the connection to the Sea Beach Line was added to the plan during the middle of construction, the plan was changed to four tracks. This section was completed in 1915. 59th Street opened on June 22, 1915, as part of an extension of the subway to Coney Island, which included the segment of the Fourth Avenue Line to the north of the station, as well as the entire Sea Beach Line to the south. The station's opening was marked with a competition between two trains heading from Chambers Street station in Manhattan to the Coney Island station, one heading via the West End Line and the other via the Sea Beach Line; the latter got to Coney Island first. Since 59th Street was an express station, the platforms were originally long, allowing eight-car express trains to stop there.