Opening of the IND Sixth Avenue Line in New York City

On December 15, 1940, the City of New York opened the IND Sixth Avenue Line, one of the most important subway expansions of the pre‑war era. Construction had begun in the 1930s as part of the city’s ambitious Independent Subway System, designed to compete with and eventually absorb the private IRT and BMT networks. The new line replaced the demolished Sixth Avenue Elevated, eliminating a noisy structure that had dominated the corridor since the 19th century. The opening connected West Fourth Street to 47th–50th Streets and 59th Street–Columbus Circle, introducing modern stations, improved signaling, and greater capacity. The line’s debut significantly relieved congestion on parallel routes and enabled better distribution of passenger flows across Midtown. Over the decades, the Sixth Avenue Line has become a backbone corridor, hosting the B, D, F, and later M services. Its construction stands as a milestone in New York’s evolution from a fragmented set of competing railways into a unified rapid transit system.