Workers at the Brooklyn Bridge station of the Interborough Rapid Transit line in 1904, with steel columns set, the trackbed open, and barrels of material stacked on the mezzanine above. New York’s first underground railway opened to the public on October 27, 1904, running from City Hall north to 145th Street, and more than 100,000 people rode it that first day. The New York City Subway grew from this line into the largest rapid transit system in the world by number of stations. Photographed by the Detroit Publishing Company. From the Library of Congress Prints and Photographs Division, no known restrictions on publication.