Preiser (Germany) makes figures from many time periods, both for model RR and diorama use. The only trouble is, they aren't cheap, especially finished. Check with your favorite hobby shop for their full catalog.
Another option, if you need to model a BUNCH of people, (especially farther in the background) is to use round head pins, wire skeletons and modeling putty to make your own. They are time consuming, but really cheap.