History of the Second Avenue Subway

The Second Avenue Subway, a New York City Subway line that runs under Second Avenue on the East Side of Manhattan, has been proposed since 1919. The first phase of the line, consisting of three stations on the Upper East Side, started construction in 2007 and opened in 2017. From 1919 to the 1960s, many distinct plans for the Second Avenue subway line were never carried out, though small segments were built in the 1970s. The complex reasons for these delays are why the line is sometimes called "the line that time forgot".

The line was originally proposed in 1919 as part of a massive expansion of what would become the Independent Subway System (IND). The Great Depression crushed the original proposal, and lack of funds scuttled numerous revivals throughout the 20th century. Meanwhile, the elevated lines along Second Avenue and Third Avenue, which the Second Avenue Line was intended to replace, were respectively demolished in 1942 and 1955, leaving the Lexington Avenue Subway as the only rapid transit line on much of Manhattan's east side. By the time the Second Avenue Line was built, the Lexington Avenue Line was by far the busiest subway line in the United States, with an estimated 1.3 million daily riders in 2015.

Construction on the Second Avenue Line initially began in 1972 as part of the Program for Action, but was halted in 1975 because of the city's fiscal crisis, with only a few short segments of tunnels having been completed. Meanwhile, construction of the 63rd Street Lines, which would connect the Second Avenue Line and the IND Queens Boulevard Line to the BMT Broadway Line and the IND Sixth Avenue Line, began in 1969. The first segment of the 63rd Street Lines, which opened on October 29, 1989, included provisions for future connections to the Second Avenue Line.

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