As part of Contract 4, the IRT agreed to build a subway line along Nostrand Avenue in Brooklyn.

[3][4][5] The construction of the subway along Nostrand Avenue spurred real estate development in the surrounding areas.

[19] At either ends of each platform, where they were extended in the 1960s to accommodate the current standard "A" Division train length of 510 feet (160 m), there are white tiles with name tablets reading "WINTHROP ST" in white sans serif face spelled on a blue background at regular intervals.

[21] Each platform has one fare control area one block apart from each other and there are no crossovers or crossunders to allow free transfers between directions.

[22] The one on the Manhattan-bound side, located on platform level, has a turnstile bank, token booth, and one staircase going up to the northeast corner of Winthrop Street and Nostrand Avenue.