I'll second that. The mouse made the money but when making a park, the train's influence is much bigger. How many trains can you find in Disneyland?
1) Disneyland RR
3) Casey Jr.
4) Big Thunder
5) Horse Drawn carriage if you count the tracks it runs on
I seem to recall a lot of other train references around the park. Mr. Toad ends up doing a head-on into a train,
Exactly right. And then one day he gets the idea to build a miniature train in his backyard, complete with train station that he borrowed from the set of one of his movies. There is the seed for scaling and theming.