Here is a picture postcard I had purchased quiete some time ago.
This is a photograph, taken possibly in the early to mid 1970's at Chicago's La Salle Street Station.
The locomotive is a "One of a kind" EMD AB-6 passenger box cab unit. It had originally pulled long distance passenger trains (pre Amtrak)
on the Rock Island line, and spent it's final years hauling commuter trains between Chicago and Joliet Illinois.