I remember when I was in 6th grade our social studies teacher asked each student in class his or her nationality. Each student promptly revealed his or her ethnic background instead of simply saying “American”. While the students were incorrect in claiming ethnic background as nationality, it shows how even as kids we viewed ourselves.
I was born and raised in the suburbs, but my particular town had its own groups in its respective neighborhoods (mostly in terms of race), as well as its own groups due to things such as religious affiliations (Irish and Italians making up the majority of local Catholics, with a large Jewish population as well).
Older people in the neighborhood would identify others, sometimes disparagingly, based on ethnic background (hence my not using the -American hyphenation). Be it the connotation of a stereotype or simply a noting of not being one of “us”, I would hear things like “Yeah, he’s Jewish” or “His son married an Italian girl”, etc.
I’m half Irish and half Polish, my father’s Irish side of the family being here for a very long time, my mother’s Polish side of the family coming to America at the turn of the century. In saying so I’m referring to my ethnic background in the way that people referred to theirs where I grew up.
I know that my cultural connections to Ireland and Poland are tenuous due to the passage of years and generations, but in my suburban neighborhood it seemed to me that ethnic identity growing up had less to do with a mother country and more to do with others also claiming that ethnic background. Eventually, Irish didn’t necessarily mean “born in Ireland”; instead, it meant that one’s ancestral roots were in Ireland, and that one identified with others whose roots were in Ireland, and how whatever that was still linked to those roots, be it religious faith or continuing traditions, was shared among those using the term. In such a sense, the -American hyphenation wasn’t necessary because it was assumed. To say that one was Polish was to say that one was an American of Polish ancestry and whatever traditions that still lived through the generations since one’s ancestors came to America.
Perhaps my limited experience growing up in a suburban town does not reflect the greater number of people, but I can imagine it being just this way in city neighborhoods that were ghettos years ago. This would also be the case in still existing ghettos with new immigrants from homeland X arriving still, but with a stronger connection to homeland X.