Series consists of records created and/or maintained by Grand Trunk properties in Quebec and New England. Two of the original five components of the Grand Trunk were the Grand Trunk Railway Company of Canada East (RG30-I-B-12) and the Quebec and Richmond Railroad Company (RG30-I-B-8) both of which had brief corporate existences prior to amalgamation in 1853. Another original component was The St. Lawrence and Atlantic Railroad Company (RG30-I-B-7) which, with its Grand Trunk leased America counterpart, Atlantic and St. Lawrence Railroad (RG30-I-B-6), gave the Grand Trunk an Atlantic outlet at Portland, Maine.
In 1864, the Grand Trunk acquired the Montreal and Champlain Railroad Company (RG30-I-B-5) which, despite the fact that it operated only 84.39 miles of line, boasted such corporate predecessors as the pioneer Canadian railway The Company of Proprietors of The Champlain and Saint Lawrence Railway (RG30-I-B-1) as well as The Montreal and Lachine Railroad Company (RG30-I-B-2), The Lake St. Louis and Province Line Railroad Company (RG30-I-B-3) and The Montreal and New York Railroad Company (RG30-I-B-4).
Other Quebec Companies either sponsored or acquired to round out the Grand Trunk's Quebec system were The Montreal and Champlain Junction Railway Company (RG30-I-B-9) and the Jacques Cartier Union Railway Company (RG30-I-B-10) in 1880, The Beauharnois Junction Railway Company (RG30-I-B-16) in 1888 and the electric Montreal and Southern Counties Railway Company (RG30-I-B-18) in 1906. The latter had previously acquired the charter and property of the unsuccessful Montreal and South Shore Auto Car Company Limited (RG30-I-B-26).
A short American line, The United States and Canada Railway Company (RG30-I-B-15) was leased by the Grand Trunk in 1889. Shortly before, this company had amalgamated with The Massena Springs and Fort Covington Railroad Company (RG30-I-B-14). In 1872 the Lewiston and Auburn Railroad Company (RG30-I-B-13) which connected the Grand Trunk's main New England line at Lewiston Junction with Auburn, Maine, had been leased by the Grand Trunk.
Two short access railways in the Montreal area were incorporated under Grand Trunk sponsorship. They were the Lachine and Hochelaga Railway Company (RG30-I-B-11) and The Lachine, Jacques Cartier and Maisonneuve Railway Company (RG30-I-B-19).
An enterprise in which the Grand Trunk officers had an interest was the abortive Montreal Island Railway Company (RG30-I-B-17).
Records are held on the North Shore Railway (Quebec) (RG30-I-B-20) now part of Canadian Pacific Railways but operated by the Grand Trunk for several years. Some of the records are also held for the associated Quebec, Montreal, Ottawa And Occidental Railway Company (RG30-I-B-21), now also with Canadian Pacific.
As well as railways, Grand Trunk companies included such businesses as the Portland Elevator Company (RG30-I-B-22), the New England Elevator Company (RG30-I-B-23), The Montreal Warehousing Company (RG30-I-B-24) and The Terminal Warehousing Company, Limited (RG30-I-B-25).
