When the New York subway system opened in 1904, no one dreamed that one day over four million people would ride it every weekday. Forced to dig or use dynamite to blast trenches for the subway through some of the hardest and most treacherous rock known, it took almost four years for workers to complete the first lines. Built almost exclusively by hand, the system was a great engineering accomplishment at the time it was constructed. With larger-than-life characters, fatal accidents, dangerous work, and tales of greed, corruption, and accomplishment, New York's subway system remains one of the greatest building feats in history.