After the first subway line was completed in 1908, the station was served by West Side local and express trains. Express trains began at South Ferry in Manhattan or Atlantic Avenue in Brooklyn, and ended at 242nd Street in the Bronx. Local trains ran from City Hall to 242nd Street during rush hours, continuing south from City Hall to South Ferry at other times. In 1918, the Broadway–Seventh Avenue Line opened south of Times Square–42nd Street, thereby dividing the original line into an "H" system. The original subway north of Times Square thus became part of the Broadway–Seventh Avenue Line. Local trains were sent to South Ferry, while express trains used the new Clark Street Tunnel to Brooklyn.