America is far from a monolith. Our states roughly equate to different European countries with vastly different cultures, foods, rights and laws.

We just speak dialects that are almost all the same and roll up under one political entity. It is not so dissimilar than the EU, otherwise.

We are, in many practical terms a forced confederation with a shared Constitution. There are those, like in the EU, who want out.

Edit: the shared single language is one of our under-recognized super-powers. I can travel this huge land mass and communicate viably everywhere. It is key to our cultural impact. It is accidental, but helpful to us. Except when we have people who dislike our impact and become hostile.