In addition to the burger previously mentioned, off the top of my head as "American cuisine" there's obviously barbecue, as well as Southern cuisine, Cajun/Creo

In addition to the burger previously mentioned, off the top of my head as "American cuisine" there's obviously barbecue, as well as Southern cuisine, Cajun/Creole, and -- while some might argue -- I'd throw in Tex-Mex and New Mexican (e.g., the state of New Mexico) as gastronomically distinct. Where you find it is, well, all over. You have to do a little research. :) But you can find really well-regarded restaurants around America for those cuisines, across a wide variety of price points.