Which New York City Subway line opened in 1932 as the first line of the Independent Subway System?

The IND Eighth Avenue Line opened in 1932 as the first line of New York City’s Independent Subway System.

The city-owned IND was built to compete with the privately operated Interborough Rapid Transit Company and Brooklyn-Manhattan Transit Corporation. Its first route ran beneath Eighth Avenue in Manhattan and connected upper Manhattan with Lower Manhattan. The line’s opening was a major expansion of publicly controlled rapid transit.

The IND Eighth Avenue Line is associated with the A and C services through much of Manhattan, while the E service joins it in Midtown and Lower Manhattan. Its original construction also created some of the system’s largest and deepest stations, reflecting the wider tunnels and generous station layouts favored by IND engineers.

The line is sometimes mistaken for the A or C line itself. Those are services; the Eighth Avenue Line is the infrastructure and route corridor used by several services.