It's not the most Pittsburgh-iest food compared to fries on a sandwich, or an original Pittsburgh creation, but it might be more popular in Pittsburgh than anywhere else. I worked with a guy who moved to PA from CT, and he never heard of Wedding soup before then. That's when I realized that it was more regional than I had known.
And if we made a list of most iconic Philly food, Cheese Steaks would probably be the topm vote getter, but those are servered everywhere, too.
www.americastestkitchen.com