The Wall Street station was built on the portion of the IRT Broadway–Seventh Avenue Line built as part of the Dual Contracts, which is the section south of Times Square–42nd Street. The line first opened as a shuttle to 34th Street–Penn Station on June 3, 1917. The line was extended south to South Ferry on July 1, 1918; the Wall Street station opened on the same date, and was the southern terminus of a shuttle on the line's Brooklyn Branch to Chambers Street. On August 1, 1918, the new "H" system was implemented on August 1, 1918, joining the two halves of the Broadway–Seventh Avenue Line and sending all West Side trains south from Times Square. As a result, shuttle service to this station was replaced by through service. This station was the line's terminus until April 15, 1919, when the Clark Street Tunnel opened, allowing service to run to Brooklyn.