> My English ancestors have precisely no bearing on the way I live my life any more than my German, Dutch or Polish (well, they came from what is now Poland, but would never have thought of themselves as polish). The child of immigrants in Germany is going to be far more German than I am despite my ancestry. American culture is undeniably real. American values and beliefs likewise.

I don't think you are disagreeing with the parent commenter as much as you think. The clear belief statement you are making and not considering your ancestry is a pretty core value of Americans (and one I like) that is not seen in other countries.

Most countries in the world automatically default to "my ancestors were X so I am X, if someone else's ancestors were Y then they are Y, no matter how many generations or how illogical this is". Example: people keep commenting how many players of African descent there are on the French men's soccer team. No one cares or talks about the ancestry of the players on the USMNT.

Ethnicity is a social construct with some fuzzy boundaries, but I don't think anyone credible tries to claim that there is an "American Ethnicity". Usually when that term comes up it's from some racist overly proud that someone in their ancestry came over on the Mayflower.

Personally I think it's one of the strengths of this country that a first generation immigrant can come here and become an American. I don't think this is very common around the world.