When we went to the Smithsonian Museum of American History, I just had to drag my friends to the transportation exhibit. It was fantastic, and I took a few (bad) pictures. Here they are:

An old streetcar.
The front of a bus, but not the rest.
 A replica of a Chicago EL station.
You could go inside an old EL train.
Awesome old-fashioned map!
A beautiful old steam train.