The story
NBSR was incorporated in November 1994 by J. D. Irving Ltd. to purchase 131.7 miles of CPR rail within New Brunswick, as CPR sought to divest its holdings east of Montreal. This purchase included the 84.4 mile McAdam Subdivision, the 5.6 mile section of the Mattawamkeag Subdivision within Canada, as well as the West Saint John Spur, Milltown Spur, and the St. Stephen Subdivision.
The actual land forming the right of way that CPR's tracks were located on was actually already owned by J.D. Irving Ltd. CPR sold all of its land holdings in New Brunswick (but not the tracks and buildings) in 1941 when it reached an agreement that saw industrialist K. C. Irving purchase the New Brunswick Railway Company Limited. This arrangement allowed J.D. Irving Ltd. to use New Brunswick Railway Co. Ltd. as a holding company to own both the NBSR as well as its U.S. sister EMRY. Ownership of the tracks in New Brunswick extends to the Canada–United States border at the midpoints of two crossings of the St. Croix River; these being the Saint Croix–Vanceboro Railway Bridge at St. Croix shared with the EMRY, as well as an unnamed railway bridge at St. Stephen shared with Woodland Rail LLC (operations contracted to EMRY).
Both NBSR and EMRY began operations on January 6, 1995, approximately one week after Canadian Pacific Railway abandoned operations of its Canadian Atlantic Railway (CAR) subsidiary on December 31, 1994. In spring 1995 Irving Transportation Services consolidated its railway operations as Eastern Maine Railway Company Limited came under NBSR operational control and NBSR trains and crews operate over both short lines in a seamless operation.
From Wikipedia’s article on New Brunswick Southern Railway, shared under CC BY-SA 4.0.4