The Warren Railroad was chartered on February 12, 1851, by special act of the state of New Jersey, to provide a connection from the Delaware, Lackawanna & Western Railroad's (DL&W) terminus at the Delaware River to Hampton, New Jersey, on the Central Railroad of New Jersey (CNJ), in anticipation of a merger between the two railroads.
Merger talks between the DL&W and CNJ broke down and on December 10, 1868, the DL&W signed a lease for the Morris & Essex Railroad (M&E), effective January 1, 1869. The DL&W then shifted their mainline off of CNJ to the M&E with a new junction at Washington, New Jersey. While the Warren Railroad was straight from the DL&W's former terminus at the Delaware River to the CNJ, its route to the M&E was circuitous. Additionally, the section between the Washington and Hampton (later called the Hampton Branch) was deemed useless.