St Lawrence and Atlantic Railroad, the world's first international railway, began service and was completed and inaugurated on 18 July 1853. The purpose of the railway was to provide Montréal, Sherbrooke and other Québec towns with access to an ice-free Atlantic port. The original plan was to build the line to Boston, but promoters in Portland, Maine, succeeded in persuading Canadians that their city was preferable.

Construction of the broad-gauge railway began in 1846, but was beset by financial troubles. The section from Longueuil, Qué, to the Richelieu River was completed in Nov 1847 and the Canadian and American sections were joined in 1853 at Island Pond, Vermont. A ferry boat connected Montréal to the railhead at Longueuil. Upon completion the Canadian section was sold, and the American section leased, to the Grand Trunk Railway.

See also Railway History.