"...Building a nation by enslaving black people..."
Look, I'm not going to sit here and defend slavery, except to say that at the time it was a thing. They also hanged people for stealing livestock, and had sword and gun duels to the death out in the street. Not okay by modern standards. You cannot apply today's morality to what essentially amounts to an alien culture.
"...eradicating the natives..."
Twenty-seven thousand square miles of land in northeastern Arizona calls that a lie.
And to be fair, when you annex territory as expansionist conquerors do, the first thing you need to do is assimilate, pacify,or eliminate the existing population. Aztecs, Incans, Arrernte, Celts, Zulu, Mandinka, Mongolians, Siamese, Teutons, Gauls, it goes on and on throughout history. Compared to most, The U.S. has not been terrible, not saying we didn't do some really shitty things, but on historical balance we're the good guys.
"...threathen other oil-nations..."
It always comes back to the oil with you people, doesn't it? If we ever saw a drop of that oil come back here, you might have a valid argument. As for who threatened who first, well that's one of the better "chicken or the egg" debates. But one thing I can tell you, it goes back to a time before oil was even a thing.
"...and calling that "Freedom"..."
You want to know what "freedom" really is? It's self-determination. It's 'government by the consent of the governed'. Liberty is the opposite of 'Dictatorship' and 'Theocracy'. If you're going to sit there and tell me that there was an Iraqi or Iranian without a gun to his child's head that would have chosen to be ruled over by a blood-soaked maniac like Saddam Hussein, or warmongering psychopath like Ruhollah Khomeini, then this conversation is ended.