The Ninth and Sixth Avenue Elevated trains, constructed in the second half of the 19th century, were built as an answer to the city's growing congestion problem. By the 1940s the Els were outdated and inefficient in comparison to the newly constructed modern subways. Between 1939 and 1958 (largely though in 1939 and 1940) the massive steel structures were dismantled piece by piece.

This series is the complete line of the Ninth Avenue El as it existed between the 1870s and 1940.