For one of the world’s largest and most important cities, New York has an odd shape; hemmed in, as it is, by rivers, and with little space above ground to channel its teeming millions from island to island. When New York was still relatively small and business was not as efficient, a casual horse ride to get around would do; but as it grew and citizens demanded better transportation methods, New York started to dig deep.

On this day, October 27, in 1904, the first IRT New York City subway line opened. A simple ceremony at Central Park belied the huge interest the new line had sparked, and 150,000 descended underground to try it out as soon as the tunnel opened.

Most of the tunnels lay fairly close to the surface, at a depth of just 30 feet, but the soft ground allowed work to proceed fairly quickly and quietly. In one notable case, a businessman on Broadway vitally interested that the rail line open as soon as possible complained that he wasn’t hearing any sounds of work — that construction was behind schedule. “Don’t worry,” was the reply, “I have had two hundred Italians under your feet day and night for these many weeks and my excavation is nearly completed.”