This question came to me after hearing (on video) someone say that
Now, I don't want to start a discussion/argument about the phrasing or attitude of the above position (it's not my position). I want to ask about the concept. I only include the above to hopefully more clearly communicate what I'm asking (by showing the seed of the thought).
Is the American settlement and expansion a historically unique pattern? That is, an obviously/distinctly different people moving into a land, and essentially completely overtaking and replacing the native people as the overwhelmingly dominant race/ethnicity/culture/etc.? Within, what, 200 years? Is that fast or slow compared to other examples?
I know there have been migrations, invasions, etc. throughout human history, all over the world. But I don't know if any of them are on the same scale as in America — such vastly different "sides" (racially/ethnically, culturally, technologically, etc., who didn't even know the other existed), and on such a vast geographical area.
If this scale is not unique with America, what were the other such massive and thorough migrations and overtakes? What nations now have a population that is completely different than the one that used to live there (without going back thousands of years)?
I think the Romans were notably different than some of the peoples they conquered and included in the empire, but Roman people didn't really move into those areas and take over as the dominant population (or even a sizable minority), right? It was mostly administrative empire — correct me if I'm wrong.
Also: I'm saying "America" here mostly meaning North America. I've not studied South America's history as much, but I think it's quite a bit different both in how non-indigenous settlement and expansion happened, and how it is currently considered (the real and perceived results).
Source: reddit post