> Neither was slavery. Was that OK too? And to clarify (though it’s worrying this point needs to be made), I mean morally.

It may well have been morally OK to most people (see: moral relativism), and since you're implying it wouldn't have been OK to you, it's worth pointing out that you probably wouldn't have done anything about it in the relevant time periods.

If you're an American you don't even need to try that hard to make moral relativism visceral: was the displacement (and far worse) of Native American tribes "OK"? I'd say no, but it isn't morally urgent enough to me or the 99%+ of Americans who are unwilling to pack their bags and return the entirety of two continents to the native descendants.