And even worse is that I am no historian and I'm probably wrong. But my direct experience contradicts a lot of the Chicago-washing of this article. For example Donato's in Columbus obviously made this style popular across the country far more than Chicago, and they weren't inspired by Vito & Nick's or something.
I bet someone right now is writing an article about how the pizza sandwich served at crappy pizza/bar places in the midwest was invented in Chicago too - even though it was probably independently invented in many locations.