The Chicago and North Western was a Class I railroad in the Midwestern United States. It was also known as the "North Western". The railroad operated more than 5,000 miles (8,000 km) of track at the turn of the 20th century, and over 12,000 miles (19,000 km) of track in seven states before retrenchment in the late 1970s. Until 1972, when the employees purchased the company, it was named the Chicago and North Western Railway.
The Grand Trunk Western Railroad Company was an American subsidiary 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.
The Terminal Railroad Association of St. Louis is a Class III switching and terminal railroad that handles traffic in the St. Louis, Missouri, metropolitan area. It is co-owned by five of the six Class I railroads that reach the city.
The Central Midland Railway, a division of Progressive Rail Incorporated of Lakeville, Minnesota, was a short line railroad in the U.S. state of Missouri, operating under lease of the former St. Louis Subdivision of the Chicago, Rock Island and Pacific Railroad. CMR operated the easternmost 60 miles of the 298-mile (480-km) Rock Island line which used to stretch from St. Louis to Kansas City, Missouri. CMR's operation of the line was performed under two separate leases from the Union Pacific Railroad and the A&K Railroad Materials Corp, respectively, from Overland, Missouri - a suburb of St. Louis, to a location just west of Union, Missouri. CMR's first leased-segment was Union Pacific's "Lackland Subdivision" which extends from "Rock Island Junction" near the intersection of Page Avenue and I-170 in Overland to a location on the north-side of Creve Coeur Lake in Maryland Heights, Missouri, known as "Vigus." The second leased-segment was owned by A&K Railroad Materials and extends from Vigus to just east of Beaufort, Missouri, with active service terminating at Union.
The following is a brief history of the North American rail system, mainly through major changes to Class I railroads, the largest class by operating revenue.