Until 1996, there were two Amtrak stations in Galesburg...GBA, on North Broad Street and the Atchison, Topeka, & Santa Fe main line, and (the present) GBB on the BN (ex-Burlington) main. After the BNSF merger and construction of a crossover for the Southwest Chief to use, passenger operations were consolidated on the former Burlington main.
Until July 1974 Amtrak was using both the Houston Union Station (now incorporated into Minute Maid Park) for the Texas Chief/Lone Star and the present Southern Pacific station (III) for the Sunset Limited. Operations were consolidated in the through station; as a Houstonian I could wish that they had consolidated into Union Station instead! (At the time, there was trackage which made that possible, but obviously a backup move into the terminal Union Station was required.)
Edit To Add: My understanding is that Houston Belt & Terminal RR, the owner and operator of Union Station in those days, charged for each switching move. Southern Pacific, on the other hand, was at the time just happy to have dumped its passenger operations on Amtrak. Somewhere in there is probably the core reason why the small-town bus terminal (okay, that's my opinion of it) was kept.