The Illinois Service is funded primarily by the Illinois Department of Transportation (IDOT) and falls under the broader Amtrak Midwest brand.

Chicago is a terminus for all three Illinois Service routes, which all have multiple daily round trips: Two proposed Illinois Service routes have been accepted by the Corridor Identification and Development Program, both in December 2023: The Quad Cities and the Rockford-Chicago portion of the Black Hawk were to have been added in late 2015[5] but were put on hold by then-Governor Bruce Rauner.

[6] They were resurrected and funded in 2019 as part of a transportation bill supported by Governor J.B.

[7] In 2023, Pritzker announced that the Rockford-Chicago train will be operated by Metra.

[8] In addition to the two new routes, a committee was formed in late 2021 to study and promote extending the Chicago–Quincy route to Hannibal, Missouri.