The seminal line was the Illinois Central and its name came because it went north-south right down the center of the state (with a key spur that connected it to a sleepy little port town called Chicago). It was seminal because it literally helped to populate the state and William Douglas of Lincoln-Douglas fame was politically instrumental in making it happen. His debating partner, Lincoln, was also involved in the railroad enterprise. According to Cortery Lincoln's biggest paycheck came from winning a railroad case. The irony was that Lincoln had to turn around and sue the railroad to get his pay.
Corery also talked about the rise of passenger service, particularly the electrified interurban lines that connected smaller towns like Monmouth and Galesburg. My wife's mother talked about traveling to Monmouth from Peoria on one of them in the 1920's. On the Monmouth-Roseville run, which was too low traffic for a regular train, there were apparently single car gasoline or diesel powered carriages called Doodlebugs. One member of our audience talked about riding on one with his grandmother when he was a boy.
And did you know that the phone company, SPRINT, was actually a spin off from the Southern Pacific RR. Sprint is an acronym for Southern Pacific Railroad Intelligent Network of Telecommunications. Read the details at this link.