Portland became a desirable destination for Montreal interests due to the port's ability for year-round shipping. In February 1845 the State of Maine granted a charter for the Atlantic & St. Lawrence Railroad and a month later the St. Lawrence & Atlantic Railway received its charter in Canada. After some starts and stops and financial backing from the City of Portland, the Atlantic & St. Lawrence eventually reached Island Pond, Vermont in February 1853 with the St. Lawrence & Atlantic reaching Island Pond that summer. About the same time the St. Lawrence & Atlantic reached Island Pond, it merged into the Grand Trunk Railway. Later that summer the Grand Trunk leased the Atlantic & St. Lawrence. Having been built to "Portland Gauge" (5 feet, 6 inches), the railroad had the disadvantage of not being able to interchange with New England's other railroads. Three years after the Maine Central Railroad converted its rail line to standard guage, the Grand Trunk reguaged its line in an amazing 12-hour project that occurred September 25-26, 1874. After many years of prosperity, high operating costs and debt from projects elsewhere on the Grand Trunk led to the railroad being absorbed into Canadian National Railways in 1923 with port-bound freight redirected to St. John and Halifax. With declining traffic, Canadian National sold the Altantic & St. Lawrence (Portland-Island Pond) in 1989 to the St. Lawrence & Atlantic Railroad.
New Hampshire rail lines in bold