Early history of the IRT subway The first regularly operated line of the New York City Subway was opened on October 27, 1904, and was operated by the Interborough Rapid Transit Company (IRT). The early IRT system consisted of a single trunk line running south from 96th Street in Manhattan(running under Broadway, 42nd Street, Park Avenue, and Lafayette Street), with a southern branch to Brooklyn. North of 96th Street, the line had three northern branches in Upper Manhattan and the Bronx. The syst