Zoomable Google Maps show the most interesting locations throughout the country where Amtrak trains switch between different lines, along with Amtrak routings serving various old Union Stations.

Chicago IC
Consolidation of all Amtrak trains into Union Station has resulted in some interesting routings for former Illinois Central trains.

Galesburg To Cameron
The BNSF merger resulted in some route consolidation west of Chicago.

Wellsboro To La Crosse
Various complications resulted in some interesting routings for Amtrak's Cardinal in northern Indiana.

The California Zephyr has had routes available on either side of the Missouri River.

During the year prior to Amtrak's creation, the newly merged Burlington Northern achieved some consolidation.

Grand Forks
The downtown station was replaced with a new Amtrak station west of town, eliminating a backup move.