A demonstration for an underground transit system in New York City was first built by Alfred Ely Beach in 1869, with a 312 foot run under Broadway in Lower Manhattan (this was later demolished when the BMT Broadway Line was built in the 1910s). The first underground line of the subway opened in October of 1904, though the first elevated line opened 35 years prior. Click through for a look at the underground subway system being constructed, from Delancey Street to the Bronx, from 1901 through 1931—and here's what a ride through the tunnels looked like back in 1905.

Today, this is what it looks like to construct a subway with a giant tunnel boring machine.