Freight and passenger lines blossomed, and in the 1830s New York City’s first railroad line connected Prince Street to the Harlem River, accelerating the city’s expansion northward from Lower Manhattan.

FOUR BECOME ONE Four competing railroads—the Hudson River, New York Central, New York & Harlem, and New York & New Haven—once linked the city to communities north and east. What happened to them? During the 1860s, Cornelius Vanderbilt bought controlling stock in the first three, forging them into a single rail empire. Today, all four are united as Metro-North.

Railroads brought people, profits…and pollution. Residents complained. So in 1854 the city banned soot-belching steam engines below 42nd Street, keeping them far from New York’s populated heart. Trains arriving from the north unhitched their engines at 42nd and towed passenger cars the last few miles downtown by horse. Despite these restrictions, the Hudson, New Haven, and Harlem Railroads were eager to expand. To coordinate their services (and save money) they agreed to share a new transit hub. With 42nd Street the southern limit for steam engines, it was the logical station location.

Grand Central Depot opened in 1871. Three towers represented the three participating railroads.

Massive skylights illuminated the 652-foot train shed of Grand Central Depot. Inside, a wealth of decorative detail, such as ornamental ironwork (right), helped to elevate the station beyond the merely practical.

Thirty years later, a new Annex doubled the Depot’s size. But double wasn’t enough. Rail traffic had quadrupled.

“The Forty-second street depot is simply an enormous nuisance” making east-west travel “a matter of imminent peril to life and limb,” declared the Real Estate Record in 1872. With 88 Harlem Railroad trains a day hurtling to and from Grand Central, getting across Fourth Avenue north of the station was difficult and dangerous. Bridges over the tracks helped. But rails still divided East from West. So in 1875, the railroad dug a tunnel from 49th to 97th Street. Gradually, the perilous tracks became posh Park Avenue.

Responding to public complaints, Vanderbilt lowered the tracks at the train yard just north of the Depot, creating an open cut down the center of Fourth Avenue (later Park Avenue) from 49th to 56th Streets. Bridges spanned the tracks for pedestrians crossing east and west. Bridges over the tracks helped. But rails still divided East from West

To help move traffic safely across its Harlem Line tracks, the railroad built beam tunnels (open at the top but spanned by iron beams) over the rails on Fourth Avenue from 56th to 67th Street, and from 71st to 80th Street. The tracks would eventually be completely enclosed by the Park Avenue tunnel.

Four tracks handled all the trains chugging north and south each day between Harlem and Grand Central. Two of these tracks ran down the central portion of partially covered “beam tunnels,” with single tracks in additional tunnels on either side.

DEPOT, STATION, OR TERMINAL? Which is correct? Is this building properly Grand Central Depot, Grand Central Station, or Grand Central Terminal? Yes. It is. All three are correct…depending on the year. The original 1871 building was Grand Central Depot. It became Grand Central Station after renovation and expansion in 1901. The new building unveiled in 1913 is Grand Central Terminal. This story originally appeared on the Grand by Design virtual exhibition here.