The confluence of tracks to the north of Grand Central was considered to be the city's "most fearful death-trap" by The New York Times in 1872, and large meetings were held to protest the deaths caused by collisions between trains and pedestrians.

[8] The preexisting track level in this section was maintained as the streets crossed over the line via iron bridges.

On June 20, the entire improvement opened, and the first trains from Grand Central to the Harlem River were witnessed by large crowds of spectators.

[14] At this time, local rapid transit trains were expected to begin operation by September 1875 and were to serve stations yet under construction.

[12] On May 15, 1876, partial rapid transit began on the Harlem Line, with sixteen trains a day running between Grand Central Depot and William's Bridge.

[18] Loud daily complaints were made to William Vanderbilt, urging him to equip these two stations on the line, which was paid in half by the city's taxpayers.

[24] At the northern end of each of the waiting rooms, staircases, which are still intact and can be accessed from both sides of Park Avenue, led to 59th Street.