The original NBR lines in the Saint John River valley were built to 3 ft 6 in (1,067 mm) narrow gauge.
New Brunswick industrialist Alexander Gibson commissioned a survey in 1866 for a railway line extending from his mill facilities in South Devon at the junction between the Nashwaak and Saint John Rivers opposite Fredericton, north to Edmundston to service timber lands which he leased from the Crown.
Part of the charter provided for additional timber land based upon construction performance, thereby making Gibson one of the largest landowners in the province.
The NBCR traced its history to the St. Andrews and Quebec Railway (SA&Q) which had a charter to build from Passamaquoddy Bay at St. Andrews north to McAdam and on to Quebec City across much of what is now northern Maine; construction plans in the 1840s from southwestern New Brunswick to Canada East halted due to uncertainty over the location of the Canada–United States border.
In 1856 the SA&Q declared bankruptcy and its assets and charter were purchased and reorganized as the New Brunswick and Canada Railway with track extended north to Richmond Corner near the newly defined border.
Although the NBCR intended to complete construction across Maine to Quebec City, it would never extend beyond Richmond Corner due to the political situation in the United States during the 1860s (American Civil War) as well as the financial situation NBCR faced with the competing European and North American Railway project.
Typical of much of its expansion in southern Ontario, CPR looked to purchase or lease existing lines rather than survey and build itself.
CPR president George Stephen was a shareholder with Gibson in the NBR and looked to extend the CP system to New Brunswick or Nova Scotia to gain access to ports in the Maritimes.
Part of the NTR closely paralleled Canadian Pacific's original NBR narrow gauge line between Cyr (just north of Grand Falls) to Edmundston, along the east bank of the Saint John River.
In 1988, citing declining traffic, CPR grouped all of its lines east of Montreal into a new internal marketing and business unit called Canadian Atlantic Railway (CAR).
Also beginning in 1988 and extending through to 1993, CAR began the process of abandoning much of the trackage of the former NBR system, citing declining traffic and bridges at Woodstock and Perth-Andover which were washed away in the spring freshet and ice jams of 1987.
The only remnant of the original NBR system is a short segment of trackage in Grand Falls, operated by Canadian National.