Now when it comes to ethnicity and culture in the United States, I notice that there is a long-held conception that the average "white" American is usually of English descent (hence the term "White Anglo-Saxon Protestant"?) or other British descent (Scottish or Scots-Irish). And "English" along "Irish", "German", and "African-American" are still to this day listed as the top four specific ancestry groups in America's population. But when I look at the US Ancestry maps, I thought that "American" would only be a nationality or a very broad national identity irregardless of race or color (despite the popular stereotypical image of an average American being "white" to the perception of those who live outside the West) in contrast to narrowly-defined ethnicities like German, Italian, Irish, Chinese, Japanese, Gujarati Indian, Russian, Tibetan, Ashkenazi Jew, Arab, Assyrian, Mayan, etc. But what I didn't know was that "American" itself is actually an ancestry label of its own for Americans who want to choose to report that in their US Census. And when I looked up what an "unhyphenated" american was on google, obviously the term didn't meant Native Americans (as that would at least be the closest thing you would have to a person who can technically be defined as "pure American" from only an ethnicity perspective), but "Americans" whose ancestors most likely originated from England like the Pilgrims during the 1600's or is otherwise of any unspecified white European ancestry, but either way chooses not to identify themselves with any country outside of the United States due to being in this nation for too many generations. And i think I read somewhere that president Theodore Roosevelt was an example of this and that most of Trump's voters are of this "group".
But on the other hand, I have a friend from real-life who is of Hispanic descent (he told me he was 3/4 Puerto Rican, 1/4 Ecuadorian, but looks fairly pale and caucasian) and he told me a few times that he would rather consider himself an "unhyphenated American" or more specifically an "unhyphenated New Yorker" without any "ethnic" descriptors attached. And from that vantage point, I was also under the impression that "unhyphenated" American could really mean someone who is an American citizen that is thoroughly assimilated into US society, culture, and language (English), and thus only considers themselves "American" above all else and doesn't identify with anything else, regardless of whatever their race, ethnicity, and origin is.
So in your opinion and interpretation, what do you think people really mean when they say "Unhyphenated" American? What defines the identity at its most basic level exactly? Why was there so much criticism and marginalization in history towards those who choose to "hyphenate" themselves, whether of European background or not? Why do some Americans dislike the idea of a "hyphenated" identity? Why is there an "American" ethnicity? What gives people the incentive to choose "American" as their ethnicity, even if they're not Native Indian? Why do some ethnic groups like French-Americans, German-Americans, or Dutch-Americans don't openly talk much about their ethnicity in America unless asked, unlike the Italians, Irish, and Chinese?
bonus question: What defines an "Unhyphenated" Canadian, Australian, New Zealander, or even British in those respective countries? How do those equivalent labels differ from America's in this case?