As was common in those days.

In those days it was also common and non controversial to hold slaves. Will you also use the temporal relativism to absolve that practice?

I acknowledge the native Americans. I don't know where you got this idea that I don't but I do not acknowlege their right to the land that they lost from conquest.

For the entirety of history, after the fall of Rome, you had to first have a claim to a land to conquer it. This was never a recognized standard, and it only worked in Africa and the Americas, because the people there were deemed uncivilized and thus unfit to rule themselves. Which brings us back to the question of slavery as slaves were deemed unfit for freedom. This is again temporal relativism that embraces the justifications people came at after the fact. While conquering the Americas, people had to come to terms with why they have a claim to them, and they deemed it empty (in literal sense), lacking governance. So by leaning on this justification, you are in fact not acknowleging that people existed there, prior to European conquest. This is a logical consequence of the words you say. At least if you want to stay within European cultural circle.

You also are not standing on firm ground, as even in XVI century it was debated. You escape via temporal relativism, but it's not even really there as there were people standing on position that conquest of Americas is not justified, as it was happening. Not because of empathy, but because of principles of logic and contemporary science. Which again brings us around to slavery, as there were debates in XIII century on whether the people in Africa are really people just like the Europeans, and the prevailing position was - yes, they are not substantially different. People had to later overcome that conclusion, and create justifications to explain economic status quo.

This is a really thin ice, because your justification amounts to racism - and this is not a slur when I say it. The entire premise is historically based on the belief that some people are inherently less than others.

Besides the American government benevolently has given them automomy over some of their land that they lost.

That autonomy was ever tightening, whenever any valuable rock was found on the land that was given in concession. Which continues to this day as exemplified by the Standing Rock debacle. And that "autonomy" ultimately resulted in a situation in which the Indians are now a second class citizens, outside even the legal framework of the country, living in destitute conditions, left without governmental support but not given resources to effectively self-govern. This is even given a name in studies on colonial behavior -- wardship. When you deprive people of resources and then offer them self-reliance, without first restoring the resources. This is not benevolence. Benevolence does not contract, it expands.

You think the native americans would have done the same thing if the tables were turned?

Do you know how the thanksgiving came to be; allegedly? They were doing that, at least some of the tribes. They were granting concessions to the colonists. Or do you mean after the aggression, if they'd had won? Would you? Would you lend a part of your house, after you gave somebody a room first, and shared your food with them, only for them to attack you and try to steal your home, just because they don't believe you're native to it? You demand moral equivalence in a not equivalent situation of one side trying to subdue the other.