In what is now the Southeast U.S., and at least to some degree in parts of the continent, they way natives reckoned kinship was also a factor.
I will use the Muskogee (the language group that includes the Creeks and Seminoles) as an example because I’ve done the most research among them, but most other southern tribes had very similar kinship norms (and the few that didn’t were usually tribes that had migrated to the southeasterrn areas of the continent far more recently than other tribes).
The Creek nation was divided into many distinct clans. Whether you were male or female, you were a member of your mother’s clan from the moment you were born until you died- that would never change, regardless of whether you never married or married 10 times. If your mother was from the Wind Clan and your father was from the Snake Clan, you were Wind Clan 100% and not even slightly a member of the Snake Clan. You would not know the secret teachings or rites of the Snake Clan, only those of the Wind Clan, which if you were a girl you would learn from your mother and her sisters or close female relatives and if you were male you would learn from your mother’s brothers (or half brothers so long as it was maternal) or her other maternal line male relatives.
The Clan you were born into was considered your family. Even if an individual was from a village you never heard of and had no known biological relationship to you, if they were a member of your clan they were as related to you in the eyes of the culture as if they were your sibling, and this was enforced in several different ways: you could not marry them, because that would be incest (again, this is true even if the person grew up hundreds of miles away and is no biological relationship, if you are Wind Clan and they are Wind Clan, you are family). If you are traveling or if you have to take refuge in another village and the only Wind Clan household there is people you have never met and they’re not doing too well as it is, they are still honor bound (and honor is everything) to take you in, because even if they’ve never met you and have never heard of your immediate family members or your village, they are your family. In some ways a fellow member of your clan was considered more your family than your own father or your own known paternal line relatives from your own village.
(I promise I will show how this is relevant to the OP.)
Okay, let’s suppose that your father is a Snake Clan member and he is the most powerful chief (mico) or shaman his clan or the tribe or even the whole Muskogee nation in memory has ever produced: that means very little to you. You are a member of your mother’s clan, and so you don’t know your father’s clan’s secrets and you look to your mother’s male relatives only for that type of instruction. At the same time, if you are the most powerful male chief in all the culture of your people and you have twenty wives and a hundred children, not one of them is a member of your clan and you have only limited say in how they are raised. You must provide for them physically, but guidance- not so much; your guidance and instruction goes to your sister’s sons only. In some ways it’s similar to a stepfather:stepchild relationship in today’s world, where a stepfather lives with his stepkids and may even provide for them financially, but he also has his own kids who he spends “quality time” with and they have their own father who they turn to for guidance and advice and male bonding and all. It’s complicated.
So, the takeaway: only who your mother was really matters, and her husband is basically just a baby-daddy. The woman rules the home and oversees the upbringing of the children and the land and house are her’s and the father, even if she loves him and bears him many children and stays with him til death they do part, is only a very limited part of the family, and this was true long before white people entered into the equation.
Now, when European men began marrying Creek and other matrilineal women, this got to be really complicated. The Creeks kept their matrilineal ways, but the Europeans also tried to make some assertions, and it became a mishmash.
Here’s the genealogy of a historically significant family where I grew up (simplified a bit):
A French officer named Marchand married a Creek woman named Sehoy. Sehoy was a member of the Wind Clan. They had a daughter, Sehoy Marchand, who was half French and half Creek (a “molatto” as often called, or ‘mulatto’ later- it was not just a term for those of African and Euro ancestry.) Sehoy had a brother or half brother named Red Shoes- for this we’ll make him a full brother and assume he was half French and half Creek. In any case, Sehoy and Red Shoes were raised more like Creeks than they were French, because they were members of their mother’s clan, and the marriage was probably sort of a matter of convenience for their father and he probably wasn’t that anxious to take them back to France with him when he returned (though he died in Alabama so it was moot, but they had no contact with his French family).
Sehoy Marchand married several times. Amongst her children were a son named Alexander McGillivray by his Scottish father (he also had a Creek name) and a daughter named Sehoy, who was also half Scottish. So her children was half Scottish, one quarter Creek, and one quarter French. In other words, three quarters European and one quarter native- they’re starting to noticeably “turn white”.
BUT, at the same time, they are technically only members of their mother’s clan. Culturally they’re actually really mixed: Alexander particularly. He is educated, he reads and writes, he’s a Mason, he privately owns land and slaves and livestock (unheard of until his generation- not only was private land ownership unknown, the notion of group land ownership was controlled by women), BUT he also is instructed in the ways of the Wind Clan by his mother’s brother Red Shoes Marchand, and he is a very powerful member of his clan and of his tribe: he travels to NYC and meets with George Washington as a chief, though he also talks to him as a fellow white planter. It’s getting complicated.
Alexander also has several wives, as befits an Indian chief, and he has children with at least one of his wives. Technically they are NOT members of his Indian clan, BUT, they are members of his Scottish clan. When he dies relatively young, the children are sent to live with his father in Scotland; neither ever returns. This was a new thing: previously they’d have been taken by their mother’s clan, and may have been in this case except that particular baby’s mama was dead.
Now let’s go down a generation:
Alexander’s half sister Sehoy (who was his half sister but there was no such thing as half in terms of her clan membership) was also 3/4 Euro, 1/4 Creek, and 100% Wind Clan. She married a Scotsman, Charlie Weatherford (among others- girl got around actually), and had a son named William Weatherford by his Scottish father, and Red Eagle by the Indians.
The reason he was given the name Red Eagle (he also had Muskogee names) was because he had red hair, and blue eyes. Like his uncle Alexander, who was his “clan father”, he was literate, a rich planter and a very powerful chief. Unlike his uncle he was a Christian, a monogamist, and to some degree considered himself an American. He was at most visibly biracial and possibly could have passed for white, BUT, he was 100% Wind Clan and, in the eyes of his tribe, his red haired blue eyed Christian Masonic planter self was as much a pureblood Creek as his great-grandmother, who was 100% Creek, and in fact he became a very powerful war chief who fought against the U.S. Government as the leader of a separatist/independence movement for the Creeks (that didn’t do too well).
There were many people like Weatherford, including his cousin William McIntosh (portrait): men whose ancestry had become far more Euro than Indian, BUT, the fact they were Indian was not trivia. It was very much a vital part of their identity, even if they were Christian (which not all were). Not all were chiefs of course, nor were they all southern: there were “white chiefs” and families in the north who were of predominantly Euro (or in some cases African, such as Micanopy among the Creeks, or Osceola who was “all of the above” in ancestry) but who also 100% identified as Indian first and foremost. (There was one northern INdian chief whose name and nation elude me at the moment but he was the son of two white people who were captured as children and adopted into the tribe, but they were considered as much members of the clans they were adopted into as if their ancestry had been 100% Indian.) The Commanches of course had Quanah Parker, but that’s getting a bit off topic.
Anyway, short story long, many families in the South and other parts of the nation may have been white or black in looks and in the vast majority of their ancestry, but that one line of American Indian ancestry was far more than just trivia: it was their identity. Native Americans didn’t reckon tribal identity or kinship or heritage the way the whites did: only your mother mattered.
And of course as the ways of the Indians mutated due to many factors, this changed a bit. You had generations who technically were no longer members of that same clan: a fellow might be the paternal line grandson of one of these people, which technically breaks the clan link, BUT, they remembered that to Grandpa his Indian identity, even though he was blue eyed and freckled and fair skinned, was very important, and so it is somewhat important to them, and they pass this on to their own grandchildren, who by now are way less than 1% of Indian ancestry, but that 1% is still mighty important.
And of course there’s the fact that claiming Indian ancestry hid a lot of African features in Southerners (and others) who were light enough to cross the color line but not quite light enough to not be questioned about it from time to time. This ALSO happened a lot (including in my own family).