It depends on how you define "uniquely created in the USA".

Frybread has a rich and complex history within the USA, and I would argue it's very much "uniquely created in the USA" but most variations have a pretty much identical recipe to hungarian lángos.

Also a lot of USA food is very regional. Hawaii has a lot of unique foods, such as loco moco, spam musubi, etc. but would be unrecognizable to most USAians.

Teriyaki dishes are technically Japanese, but the Pacific northwest has taken the concept and run with it to the point where it's now it's own unique creation. It also has cheese zombies, jojos, Seattle dog, huckleberry everything, etc.

Southwest USA and Mexican have a lot of overlap but are also just as distinct with "Tex-mex" being it's own culinary thing. Puffy tacos, chili con queso, cornbread, cowboy caviar, nachos, etc.

Midwest, Alaskan, southern, east-coast, Puerto Rican, etc. all also have their own unique culinary traditions at this point with lots of micro-regional distinctions within them.

However, they aren't marketed, advertised or popularized in the same way that things like "Chinese food" is. Despite "American-Chinese food", like general Tsao, or orange chicken, being very much it's own genre that is unrecognizable as either traditional/old recipe USA or Chinese foods.

To discover many of these things you can't just "tourism" through but have to actually try to know and understand the people and places.

Conversely, it's not like Italian food stops being Italian due to its use of "new world" food stuffs like tomatoes, or pasta is any less "Italian" despite it just being Chinese noodles with a few changed ingredients.

If you insist on playing that game you'll find nothing is unique.