91st Street Station was one of the original 28 stations in the New York City Subway. Located at the intersection of West 91st Street and Broadway, it lies in the heart of Manhattan's Upper West Side. It was opened in 1904, and decomissioned in 1959.
I live very close to the station, and like to learn about the history of the subway and the city.
Part of the appeal of investigating this station is that while the street above it is heavily trafficked, as are the subway lines that pass through, it is very easy to ignore.
There are almost no traces of it on the surface - one has to know where to look to see what is left. The old platform is partially visible from local 
trains, and is largely intact, but no one really notices it in the dark of the tunnels.
It was one of the original stations, but was basically doomed from the start, being a mere five blocks from its neighboring stations, a shorter distance than any other uptown station.
No one really minds that it is gone but, its "my" station.
This page aims to collect all the resources I can find regarding the station, and provide context and modern images and diagrams. The Wikipedia page has plenty of information and citations. There are additional resources on Joseph Brennan's site as well as the NYC Subway wiki.
Primary construction of the station appears to have mostly taken part from the latter half of 1902 through 1903, based on the dates of available photographs of the construction. A November 1903 New York Times article suggested all track was laid in the area: "on the main line of the tunnel, extending from City Hall Park to One Hundred and Fourth Street and Broadway, there remain only three short stretches in which tracks have not been laid." It also suggests that there was little surface-level disruption by that time: "... and in upper Broadway the places where excavations continue to disturb traffic are few and far between".
The station was built with one entrance for each of the two sides, with direct access to the platform level. There was no mezzanine, and no underpass, much like 86th Street.
The downtown entrance kiosk was located at approximately 2461 Broadway, on the north-west corner of the Broadway-West 91st intersection. It is visible in the photograph taken of that address around 1940 by the NYC Tax Department (original image) and in a photograph taken in 1955 by Alfred Loonam from a similar angle. A 1957 survey photograph offers another perspective, facing south. It was taken during platform extension work on the line, immediately preceeding the closure. We can see in the modern recreation of this photo that there is a grate above where the stairs were previously. Air can be felt flowing when trains pass by.
The uptown entrance kiosk was located at approximately 2450 Broadway, on the south-east corner of the Broadway-West 91st intersection. It is partially visible in the photograph taken of that address around 1940 by the NYC Tax Department (original image). The entrance is in front of Hotel Greystone, which is still present in 2025 as the Greystone Apartments. In 1955 Alfred Loonam took a photograph of the entrance, facing north.
TODO: Describe materials etc.
