Located within the commercial docks at Hakin, it was constructed to service an anticipated transatlantic trade between Milford Haven and New York City.

Isambard Kingdom Brunel had a vision of connecting London to New York City via a railway through Wales and then to a commuter port.

The failure to complete Irish rail links meant that the terminus was modified to a location on the Milford Haven waterway.

Construction began in August 1856 and lasted five years, finally completed in 1863,[2] when the line was connected to the South Wales Railway at Johnston, and a station at Milford was opened.

It connected with a pier, which was reached via a lifting bridge at Castle Pill; the junction with the Milford line opposite the station.