The International was a named passenger train operated between Chicago and Toronto. It was originally an overnight train operated by the Grand Trunk Railway of Canada and its successors the Canadian National Railway and Grand Trunk Western Railroad, running as far as Montreal. The train was cut back to Port Huron, Michigan, in 1970 and discontinued in 1971.

The Grand Trunk Western Railroad Company was an American subsidiary of the Grand Trunk Railway, later of the Canadian National Railway operating in Michigan, Illinois, Indiana, and Ohio. Since a corporate restructuring in 1971, the railroad has been under CN's subsidiary holding company, the Grand Trunk Corporation. Grand Trunk Western's routes are part of CN's Michigan Division. Its primary mainline between Chicago and Port Huron, Michigan serves as a connection between railroad interchanges in Chicago and rail lines in eastern Canada and the Northeastern United States. The railroad's extensive trackage in Detroit and across southern Michigan has made it an essential link for the automotive industry as a hauler of parts and automobiles from manufacturing plants.