Question: The first railway in British North America, the Champlain and St. Lawrence Railroad, was built when to track gauge, However the promoters of St. Lawrence and Atlantic Railroad, (intended to connect Montreal to the ice-free port at Portland, Maine) decided to use , setting a precedent for the colony for several decades, The St. Lawrence and Atlantic Railroad (reporting mark SLR) , known as St-Laurent et Atlantique Quebec (reporting mark SLQ) in Canada, is a short line railway operating between Portland, Maine, on the Atlantic Ocean and Montreal, Quebec, on the St. Lawrence River?
{'answer': 'mid-1830s', 'supporting_facts': [['Track gauge in Canada', 0], ['St. Lawrence and Atlantic Railroad', 0]]}