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.

The adoption of the former New York Central Peoria & Eastern line west of Indianapolis, despite abandonment of a segment immediately west of Indianapolis, requires an interesting routing via the former Pennsylvania Railroad.

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

A railroad relocation project finally eliminated the former Monon route operating down the middle of Fifth Street.

Battle Creek
A street crossing elimination project resulted in the consolidation of the former New York Central traffic onto the former Grand Trunk Western line.

The old Michigan Central station was abandoned for many years, with Amtrak now serving a station along the former Grand Trunk Western Mount Clemens Subdivision, which has enabled extension of service via the Holly Subdivision beyond to Pontiac.