Lines are grouped into historic operating divisions. As passenger service declined during the 1950's, many divisions were consolidated.
Chicago Division (Chicago-Fort Wayne)
Clover Leaf District (Indiana)
Clover Leaf District (Illinois)
Peoria Division (Illinois)
Peoria Division (Indiana)
Sandusky Division (Lafayette-Ohio State Line)
New Castle Division (Fort Wayne-Rushville)
Indianapolis Division (Michigan City-Indianapolis)