I understood everything you typed and in general I agree that what you said as it's truth. But in the case of American history things didn't quite work out that sameway. I'd say that what you typed sorta explains how the migraters from Europe treated Natives here in the 1600s. Then greed kicked in and made matter worse for those Natives.
Sami and Native Americans are a good comparison (though Sami aren't necessarily natives, and there's a long debate about that), though I'm unsure of how nomadic the various tribes were. However, the thought about african slaves exceptionality to this is something I'm highly suspicious of (not that it's not necessarily so, as exceptional phenomenon are also parts of history, but exceptionality in human behavior is problematic unless researched at its core). First of all, to use American history would fail to understand "the origin", which would be the circumstances of slave trade in Africa. If you view it in that context, in pre-enlightenment era, it becomes far more closer to the concept of a sense of superiority and it becomes more an issue of stratification. Such division might further evolve by being reinforced by group . The economic incentive in the mind of slave owners further reinforces the need of division. This doesn't however magically translate afterwards, unless we want to believe in a fatalistic "America will always be inherently racist". Then there's modernity and the focus on eugenics that arose and which carries the concept of "hereditary sin".
But with Africans and their later generations born in America, the evils that were done didn't have much to do with "misunderstood positions of superiority, a sort of self-perceived benevolence and sympathy for people perceived as lesser than you" as you put it. If it was just that then those people wouldn't have made it illegal in the 1600s and 1700s to teach a slave how to read. In the 1900s it wouldn't have been illegal for a black person to marry a white person. They wouldn't have created black codes laws after the Civil War to suppress the freedom, liberty, and happiness of black people.
Again, drawing lines between centuries is a dangerous thing, it's causally approaching maximal uncertainty, treating an object as if completely disclosed from numerous historical influences and as if historical context just transfers over perfectly.
"If this ... then you wouldn't see this in xth century and this in yth century" is not a good way of taking a complex origin of a phenomenon of prejudice and trying to disprove it. The effect doesn't necessarily have a symmetrical relation with cause. Just as the concept of white people and "colored people" developed, it can also be undone, by dissolution of the categories and evolving beyond them. Of course, this isn't something that just happens, as what divides us also strengthen us. (i.e. dividing people by the color of their skin, reinforces the unity and the sense of agency in regards to the color of your skin) There's no quick solutions and from my experience things are better with dialogue and trying to tear down walls and not fall into our respective categories.
None of that has to do with "the gulf between groups/nations or the hubris of a self-confident technologically advanced nation in facing states/groups with customs that in their context is ludicrous or things caused by being on the unfortunate end of technological development." Black people went from being slaves to being inventors in the matter of a decade. From Lewis Latimer's (his parents were runaway slaves) help co-creating the invention of the light bulb (1880s), to Elijah McCoy's (his parents were also run-away slaves ) invention of the lubricating cup for trains(1872) and he also invented and patented the lawn sprinkler(1920s). The phrase "The Real McCoy" was literally made because of this black man and it described how good his invention was. To Garret Morgan who would create the first ever gas mask in 1912. Unfortunately after 5 or so years when police and fire departments found out that the gas mask was invented by a black man, some of those departments refused to use them. But the US Army decided to use them in World War 1 and that changed history. To Daniel Williams who was the first human ever to perform open heart surgery. He did this in 1893!
In your historical synthesis, you're thinking too loosely about prejudice being driven by a very reductionistic causal chain. When reinforced with the concept of earlier technological prowess, an outward identity marker, economic benefits and a concept of exceptionality, the development of refusing the validity of black people's accomplishments becomes quite a plausible scenario. You're not really excluding the premise with your examples. Unless you want to say "black people have been mistreated", which you'll find very few people objecting to. Your examples do however also provide that things aren't as black and white, as many of the feats are examples of progress.
Btw, some of your examples are obvious misrepresentations, especially the last one, after researching it a bit. They are some impressive feats, one doesn't need to misrepresent them.
Notice how much black Americans changed the country, yet still didn't have basic rights in America. There are so many more people I could use as an example too. The average white person of that day didn't care how smart, noble, or advanced technologically you were. If you were black, you were viewed darn near equal to an animal.
Treating the "average white" as a group is just as disingenuous as treating the "average black" as a group. Your examples can't actually conclude from the reception to the concept of an "average white" and there's numerous problems with not attempting to understand the various perspectives of white americans leading to their view of black americans. If we care about the subject of socioeconomic factors leading to skewing a lot of statistics, then it doesn't help to dismiss the historical context of the white americans' perspectives and how divided their perspectives were.
A problem with what you've been proposing is that it drives by the same fatalism that drove a lot of the perspectives on black people, namely the perspective of people technologically behind being "inherently backwards" or "losers of history" (I have a big problem with the concept of a "right side of history" and its teleological nonsense). The thought that something is inherently transferred in its essence over time. That's why I'm skeptical of the concept of some perceived evil intent (which I've not seen any great evidence for and treads on the problematic grounds of "initial cause") somehow means that is the essence of a phenomenon in the future. It fails in most analogies as a concept, even in binary examples, "the door at my parents' house has always been open, why should I believe it would change in the future?" (concluding that a phenomenon is ahistorical and static, when things do indeed change and urbanization, changes in population, prejudice, increased crime levels and sense of community might make your parents lock their doors) Most of my objection is, however, to the brazen use of "History says this is a lie", which I can't stand behind. History is a revolving door, you think you've got it and then the damn door smacks you in the ass. When I write my research, I try to facilitate numerous explanations and debunk them according to evidence, but I might be disproven shortly after. Or I might face a case of someone taking a different perspective, which becomes more about arguing on which perspective fits best to a certain topic being explored, there might be methodical and theoretical approaches that I might disagree with, but which I'll also have to understand the merits of.
I do mostly history on minorities and persecution, in a European perspective, but I might consider to do some larger synthesis, grabbing in a wider historiography and testing various perspectives. I've already been thinking to do some work on missionaries, racism and feminism, but a part of this sounded interesting. A part of me wants to do something akin to Braudel's
La Méditerranée or perhaps going fictional with a historical basis. My work is mostly 19th and 20th century history, so a larger time frame might be interesting to catch the longue durée. Might quit my teacher job and go for my doctorate if I find some fertile ground.
