The Salem Railroad was incorporated on March 14, 1856. Construction was completed in 1863, stretching from Elmer to Salem, and leased to the West Jersey Railroad on January 1, 1868. The Swedesboro Railroad was built by WJ from Woodbury to Swedesboro, a distance of, and completed in October 1869. In 1883, the WJ's Woodstown and Swedesboro Railroad built a line from the end of the Swedesboro Railroad to Riddleton Junction on the Salem Railroad. On May 4, 1896, the Pennsylvania Railroad consolidated its southern New Jersey operations under the West Jersey & Seashore Railroad. In 1931, New Jersey's public utility regulators ordered consolidation of PRR and Reading RailroadSouth Jersey operations. The PRR bought two-thirds of RDG's stock, and the consolidation, Pennsylvania-Reading Seashore Lines, became effective June 25, 1933. Passenger service on the Salem Branch ended December 30, 1950. PRSL was acquired by Conrail in 1976, including what had been known as Salem Secondary Track. Following the division of Conrail in 1999, it was designated part of Conrail Shared Assets Operations. The southern of the line and the Glass House Spur to the port was sold by Conrail to Salem County in 1985, which in 1988 leased the line to Pioneer Railcorp subsidiary West Jersey Rail Company in 1988 to operate. In 1995 operations of the Salem County Branch Line were assumed by SRNJ. In 2009 U.S. Rail Corporation took over operations. In 2012 the county reassigned the contract to SRNJ. In Swedesboro, SRNJ maintained a yard and connected with CR via the Swedesboro Industrial Track and Salem Running Track. In 2018, SRNJ leased the section of the Salem Secondary between Swedesboro and Woodbury from Conrail, with an interchange with Conrail established in Woodbury.
Rehabilitation and upgrades
Line condition has been rehabilitated due to funding from various county, state, regional, and federal funding appropriations since the county takeover. Much of its infrastructure is antiquated and allows for maximum speeds of. A 2010 New Jersey Department of Transportation report anticipated increased port and freight activity in South Jersey. In 2011, the South Jersey Port Corporation, Conrail, and Salem County received $18.5 million in federal money to partially fund rail infrastructure improvements for the Salem County Branch Line and a new link from the Penns Grove Secondary to Port of Paulsboro, and retrofitting of the Delair Bridge, the most downstream rail crossing of the Delaware River and crucial link between the national rail network and ports at Salem, Paulsboro and Camden. With the federal appropriation and local matching funds, $1.55 million will be used for upgrading trackage from Swedesboro to Salem, expected to be completed by 2015, and $3.5 million to replace the trestle at Oldmans Creek, to be finished by 2014. Train speeds will be improved to. Prior to 2013, NJDOT had deemed various project work along the Salem Branch eligible for future state funding. In 2012, the South Jersey Port Corporation, Conrail, and Salem County sought another $21 million in federal or NJ state grants in order to complete all needed upgrades for the Salem County Branch Line. NJDOT's 2013 Rail Freight Assistance Program approved 90 percent funding for $2,250,000 for rehabilitation of the Salem Shortline Running Track through Mannington Township, Pilesgrove Township, and Woodstown. In November 2017, a project to improve rail access at the end of the line in the Port of Salem was begun.
