Since the last Ice Age, the only safe route into Canada's interior during the winter started at the Bay of Fundy and followed the main rivers north to the St. Lawrence River through what is now New Brunswick. Aboriginal people used this route as a major highway in all seasons and the great imperial powers followed their lead.
The route also played a key role in the American Revolution as well as the Aroostook War of 1839 that saw bodies of troops lining each side of the border extending from St. Andrews (NB) and Calais (ME) to Madawaska. In 1842, the Grand Communications Route and the Webster-Ashburton Treaty determined the location of the CanadaUS border.
It is still in use today: the Trans-Canada Highway and Route 7 follow its path. As well as telling the story of the Grand Communications Route from the earliest human habitation of the area, The Road to Canada describes the historic sites, forts, blockhouses and other historic remains that can still be visited today, including Martello Tower (Saint John), the Fort Hughes blockhouse (Oromocto), the Fort Fairfield blockhouse (Fort Fairfield, ME), Le Fortin du Petit-Sault (Edmundston), the Fort Kent blockhouse (Fort Kent, ME) and Fort Ingall (Cabano, QC).
The Road to Canada is volume 5 in the New Brunswick Military Heritage Series.