It's not just in the US, either. Every state of Australia has a Springfield and memorably I was once snowed in in Springfield, New Zealand. There's several in South Africa and plenty in the UK. You'll also find a Springfield on the outskirts of Dublin. Sadly I can't find a Springfield in Asia or South America, though there are businesses and buildings with that name - there's a Springfield Inn at Causeway Bay in Hong Kong and a store named Springfield in Singapore and Manila. Meanwhile you can go to the Springfield Bar in Posadas, Argentina.
If only there were a place called Cyprus in 37 states.