All of the foods, with the exception of the tacos, enchiladas, and such, were staples in our household, in a small town in the Upper peninsula of Michigan. I thought we were pretty culinary isolated. At least for U.S. cuisine, we actually had quite a variety when I compare it to the staples some of you have mentioned for you areas. Who-da-thunk-it?
If there ever was a unique American dish, it has to be things made with corn, be it hominy, corn on the cob, corn pudding, Johnny Cakes, Corn pone, Corn Chowder, Corn Bread, Corn coating for meats and fish, corn meal mush, etc.
Then again, we make a host of things from almost every food available to us. We blend techniques and flavors from all over the world. To be fair, Unique American cooking is the amalgamation of flavors and techniques, often with a crazy spin on the original. My MIL's tacos won't be found in any restaurant. They sure are yummy. You also won't find my egg roll recipe anywhere else. But everywhere I serve it, it takes the stage. It's what we do best, adapt things to our own tastes.
Seeeeeeya; Chief Longwind of the North