[2] In 2008, United States Senators Tom Harkin and Chuck Grassley of Iowa and Dick Durbin and Barack Obama of Illinois sent a letter to Amtrak asking them to begin plans to bring rail service to the Quad Cities.

[3] In October 2010, a $230 million federal fund was announced that will bring Amtrak service to the Quad Cities, with a new line running from Moline to Chicago.

[6] After being on hold for over a year, IDOT moved forward with the project in order to prevent losing the $177 million in federal funding for the passenger service.

[7] In July 2019, a new transportation bill was passed by the Illinois state legislature, supported by Governor J.B. Pritzker, with $225 million was appropriated to begin this service.

[10] In December 2023, the Federal Railroad Administration accepted an application by IDOT to enter the Chicago–Moline route into its Corridor Identification and Development Program.