The connection opened on December 1, 1955,[4] and permitted BMT trains from Brooklyn to use the IND Queens Boulevard Line; the first service to do so was the Brighton Beach Local via Tunnel (1, now Q).
The first service to use the connection was the daytime 1 local via Montague Street Tunnel, which became the QT in the early 1960s.
The QT was rerouted to Astoria–Ditmars Boulevard on January 1, 1961, and the RR was sent through the connection during daytime hours.
The EE was created on November 26, 1967, when the Chrystie Street Connection opened and the RR moved back to Astoria.
On August 27, 1976, the N was extended through the connection, absorbing the EE; this change sent late night and weekend trains through the tunnel for the first time.