Inaugurated by the Canadian Pacific Railway (CPR) as a "limited stop" service on September 25, 1955, "The Atlantic Limited" used numbers 41/42 (westbound/eastbound) and took the schedule and equipment for what were previously numbered trains between Montreal, Quebec (Windsor Station) and Saint John, New Brunswick (Union Station). The service operated overnight using the CPR's former International Railway of Maine line which formed the direct route between Saint John and Montreal. Although this was CPR's first named passenger train to the Maritimes, daily passenger service had been offered since 1889.