thumb|Abandoned CPR passenger station at [[Greenville, Maine|Greenville Junction, Maine, opened in 1889. The last passenger service using this station ended on December 17, 1994, with discontinuation of Via's Atlantic service. In the distance is a trestle leading to the former junction with the Bangor and Aroostook Railroad at Moosehead Lake.]]
The International Railway of Maine was a historic railroad constructed by the Canadian Pacific Railway (CPR) between Lac-Mégantic, Quebec, and Mattawamkeag, Maine, closing a key gap in the railway's transcontinental main line to the port of Saint John, New Brunswick.
Winter alternative to Montreal
The CPR completed its route from Montreal, Quebec, to Vancouver, British Columbia, in 1885. In the decades prior to the use of ice-breaking ships in the Gulf of St. Lawrence and St. Lawrence River, the port of Montreal was closed from December to May, limiting any advantage that the railway might have over its competitors.
CPR's primary Canadian competitor, the Grand Trunk Railway (GTR), managed to avoid the winter ice problems in Montreal by using the ice-free port of Portland, Maine, accessed by a route constructed by the St. Lawrence and Atlantic Railroad which the GTR had purchased in the mid-1850s.
Construction under Chief Engineer James Ross began in 1886–1887 and proceeded in both directions from various points on the route. The new line opened in June 1889 and CPR obtained trackage rights over the Maine Central from Mattawamkeag to Vanceboro, and purchased the New Brunswick Railway to acquire control of the route from Vanceboro to Saint John, as well as a branch line network in western New Brunswick and northern Maine.
In addition to interchanging with CPR at Vanceboro and Mattawamkeag, the Maine Central had an interchange with the CPR from 1906 to 1933 west of Greenville Junction where the Kineo branch crossed at Somerset Junction en route to Kineo Station connections with steamboats serving the Mount Kineo House.
Two logging railroads also interchanged with the International of Maine Division. There was an interchange at Jackman with Jackman Lumber Company's Bald Mountain Railroad from 1915 to 1926, and with the Ray Lumber Company (later Indian Lake Lumber Company) railroad at Ray Siding near Caribou Stream in Bowerbank Township from 1912 to 1929.
Ray Lumber Company locomotives
{|class="wikitable"
!Number
!Builder
!Type
!Date
!Works number
!Notes
|-
|1
|Lima Locomotive Works
|Shay locomotive
|21 August 1912
|2560
|purchased new; sold to Appalonia Lumber Company of Pelahatchie, Mississippi
|-
|2
|Manchester Locomotive Works
|4-4-0
|May 1884
|1195
|formerly Bangor and Aroostook Railroad #201; purchased 1913
Traffic declines
In 1955, CPR created a limited stop express passenger train named The Atlantic Limited. This daily train operated overnight from Montreal to Saint John and vice versa, with full service diner, observation and coach/sleeper cars.
Government investment in the 1970s for an intermodal container terminal and various improvements at Saint John resulted in some freight traffic increases and CPR invested in infrastructure improvements over the route, however by the 1980s, it was in severe decline as changes in shipping patterns and cargo logistics saw CPR make less and less return on the line.
In 1978, Via Rail Canada took over operation of CPR passenger services and The Atlantic Limited was changed to become the Atlantic and service was extended east from Saint John to Halifax. Passenger traffic increased but government cutbacks in 1981 saw the train discontinued, removing passenger service from the Montreal-Saint John route for the first time since the route opened in 1889. The Atlantic was restored in 1985 and remained in daily service until 1990 and then tri-weekly service thereafter.
In 1988, CPR organized all its lines east of Montreal into Maine and the Maritimes (including its Dominion Atlantic Railway subsidiary in Nova Scotia) under a new subsidiary called the Canadian Atlantic Railway (CAR). The CAR experiment was short-lived as its lines were still losing money, despite abandoning many of its small rural branch lines in western New Brunswick and northern Maine. CPR applied in 1993 to abandon the mainline from Montreal to Saint John but was refused by government regulators.
Abandonment and sale
In 1994 it applied again for abandonment and permission was granted for the end of that year. Shippers and communities along the route were upset and urged CPR to sell the line, which it finally did in sections on January 1, 1995. In advance of the pending abandonment and later sale of the line, Via Rail discontinued passenger service with the Atlantic on December 17, 1994, and the line has not had dedicated passenger service since then.
The section from Saint John to the Maine–New Brunswick border was purchased by New Brunswick Southern Railway, a subsidiary of J. D. Irving Limited, an industrial conglomerate and major traffic source in Saint John. The section from the Maine-New Brunswick border west to Mattawamkeag (where it interchanges with Guilford Rail System) and on to Brownville Junction (where it interchanges with Bangor and Aroostook Railroad) was also sold to a JDI subsidiary, Eastern Maine Railway. West of Brownville to Montreal, the route was purchased by Iron Road Railways, the corporate owner of the Bangor and Aroostook Railroad.
The bankruptcy of Iron Road in the early 2000s saw the western part of the system taken over by the newly organized Montreal, Maine and Atlantic Railway (which filed for bankruptcy protection in August 2013), while JDI continues at the eastern end of the route.
Fortress Investment Group purchased the trackage owned by the Montreal Maine and Atlantic out of bankruptcy. This includes the portion of the International Railway of Maine from Brownville Junction to the west. Operations began in 2014 as the Central Maine and Quebec Railway.
As of June 4, 2020, Canadian Pacific has purchased the entire Central Maine and Quebec Railway and has begun the process of integrating the former CM&Q lines. This includes the former Bangor and Aroostook lines owned by the Central Maine and Quebec which had no prior ties to Canadian Pacific.