The first regularly operated
subway in
New York City was built by the city and leased to the
Interborough Rapid Transit Company for operation under Contracts 1 and 2 of the
Dual Contracts. Until 1918, when the new "H" system that is still operated - with separate
East Side and
West Side lines - was placed in service, it consisted of a single trunk line below
96th Street with several northern branches. The system had four tracks between
Brooklyn Bridge – City Hall and 96th Street, allowing for local and express service on that portion. Under the "H" system, the original line and early extensions are now as follows: