The Twilight Limited was a named passenger train in the United States which initially operated between Chicago, Illinois, and Detroit, Michigan. The New York Central Railroad introduced the train in 1926, and it continued until the formation of Amtrak in 1971, although it lost its name in 1967. Amtrak renamed the train St. Clair, feeling that the name "Twilight Limited" had undesirable connotations and imagery for a company trying to save passenger rail service. Amtrak revived the name in 1976 for a new train frequency on the Chicago–Detroit corridor, and kept the name until all trains on that corridor were renamed Wolverine in 2004.

Michigan Services are three Amtrak passenger rail routes connecting Chicago, Illinois with the Michigan cities of Grand Rapids, Port Huron, and Pontiac, and stations en route. The group falls under the Amtrak Midwest brand and is a component of the Midwest Regional Rail Initiative.