Construction contracts for the Nassau Street main line in Manhattan were awarded in early 1907, despite no determination of the operator once completed.

The line was assigned to a proposed Tri-borough system in early 1908 and to the Brooklyn Rapid Transit Company (BRT) in the Dual Contracts, adopted on March 4, 1913.

[6] The New York City Board of Estimate approved funds for the project in July 1926,[7] and the extensions were completed in 1927, bringing the length of the platforms to 535 feet (163 m).

[14] The closed platform has been used for fashion shows, a police terrorism drill, and for dozens of movie and television shoots yearly.

The eastern mezzanine is reached via three flights of stairs or a single escalator from the open platform.

The east end of the station has a high ceiling; this was to allow for a proposed subway line to pass through it.

This section had an opening in the wall separating both platforms to bracket the new line, but has been covered with plywood.

Due to the depth, there were escalators that were provided in the original construction, one on each platform running to the east mezzanine.