It’s hard to believe that New York City’s comprehensive (and complicated) subway system all started with a single train line called the Interborough Rapid Transit, or IRT, which began operation on October 27, 1904, running from City Hall up to 145th Street. Pictured: The scaffolding barely stands inside a newly excavated tunnel in 1900.

It’s hard to believe that New York City’s comprehensive (and complicated) subway system all started with a single train line called the Interborough Rapid Transit, or IRT, which began operation on October 27, 1904, running from City Hall up to 145th Street. Pictured: The scaffolding barely stands inside a newly excavated tunnel in 1900.