Nearly 150 years ago, something quite momentous happened in New York history: the first subway line was opened to the public. The system was the invention of Alfred Ely Beach and his company Beach Pneumatic Transit Company. Beach put up $350,000 of his own money to build the first prototype and tunnel and his company managed to put it together, somewhat covertly, in just 58 days. The tunnel measured about 312 feet long, eight feet in diameter, and was completed in 1870.
more on the history of NYC's 1st subway line here