I went through something a bit similar when I was 18. I had just started in college and went to visit my (widowed)
Gramma. On day, as she absently flipped through some snapshots she found in the bottom of a drawer:
“Oh, look! Here’s one of Carroll [Grampa] when he was little. And with his mother!”
“His mother? I don’t think I’ve ever seen a photo of her.”
“Well, adoptive mother…”
Pause
“Adoptive mother?”
“Well, grandmother, really…”
Pause…
So out it came. Grampa was a bastard, in the original sense of the term (my father and I both loved him to death).
Grampa’s mother was 15 when she was knocked up by Man Unknown. Her parents raised him as if he were their child, a feat made easier since they in fact had another baby about three years later.
Grampa had no idea of anything - as far as he knew, he was the seventh of eight children. In fact, his “brothers and sisters” -even his little brother - were his aunts and uncles.
He only found out the truth after his “mother” and “father” were both dead (the former when he was 12, the latter when he was 14). At that point he went to live with his “older sister” (actually his aunt) Irene, who by that point was married. She raised the three boys who were still school age, until they graduated from high school. Somewhere during this time, Grampa learned that his “sister” Alice was, in fact, his mother, a terrible humiliation for a young person in the 20s.
(Alice, in fact, did virtually nothing to raise my grandfather, leaving the burden entirely to her sister.)
He successfully kept the secret from my grandmother as well, at least until six years after they married. By then, gramma was was pregnant with my father (their only child), and “Aunt Alice” suddenly informed her that she was the child’s grandmother. Gramma was shocked, needless to say, and affronted when Alice turned into the mother-in-law from hell, after having done nothing to earn the position! I think Gramma was a little peeved with grampa, only because he didn’t tell her - but I’m sure she understood the shame he felt.
Now, I know that “Aunt Alice” was of scandinavian descent, and although we know nothing of the father it’s a safe bet (this was Minnesota) that he was, too. Gramma was German-from-Russia, Odessa to be exact, and grew up in North Dakota speaking German and English.
On the other side - well, that’s Southern. That means mixed English/Scottish/Welsh, along with Cherokee. Unlike other posters here, my family’s always been very proud of the fact that my great-great-great-great-grandmother (I think that’s the right number of greats) was Cherokee. Usually it’s mentioned in the same breath as my great-great-great-grandfather, who (not-very-voluntarily) fought for the Confederacy at Glorieta Pass, New Mexico and, when defeated, walked some eight hundred miles home to East Texas.
(Tom - I think the answer to your “where are the Welsh?” question is that not as many of them came, and those who did generally arrived several generations earlier than the Irish and so intermarried out of identity).
Culturally, I identify with the German-from-Russia more than anything else. Gramma taught me a few phrases of dialectic German, and much of the foods that I grew up with are from this community. To me that’s really what’s important - what did you know when you were a child?