The reason there weren't as many Indian dead as European dead in the World Wars is because there weren't as many Indians.
Not true. Millions of Indians died from "European" diseases, not a policy of genocide. Many, many others assimilated into the new culture, became Christians and settled down into more "civilized" pursuits with the same rule of law and rights as other Americans rather than continue the "old" ways - ways which also consisted often of constant tribal warfare which racked most of the old Indian societies.
The Cherokee Trail of Tears was genocide, pure and simple.
This was a lamentable atrocity but much more the exception than the rule. Indian and Western cultures could not mix and one had to win out - just as Western and Muslim cultures must have one which eventually prevails (a contest I would be more exercised about, if I were you).
Slavery was a legacy of the colonial past,...
Although true, slavery was not at all unique to America. The American Indians themselves had slaves. Slavery was a worldwide, ages old phenomenon eventually eradicated in most of the West through Christian agitation and Western political action - and in the case of the United States, a bloody Civil War.
... (slavery) which the US was perfectly willing to accept and exploit for four score and nine years,
Slavery was a compromise done to facilitate the founding of this country and done so only because it was a fait accompli in certain areas, not because it was deemed desirable by all - or even most. It was anticipated by many it would eventually disappear peacefully. The continuation and spread of slavery (some other factors, too, but slavery as an institution was one of the most notable) eventually led to attempts at secession from the American Union by most slave-holding States. That failed and slavery was immediately and universally abolished.
...and then to maintain apartheid for another hundred. THAT was not the fault of the British. It was homegrown American evil, pur et dur.
That was an outgrowth of political and cultural reaction by "losing" elements of the Civil War and it's carpetbagger aftermath. The defeated side was embodied by the Democrats who took over the reins of political power in the 1880s and instituted racial segregation locally, after the Union Occupation ended. This eventually ended peacefully and through the rule of law. America as a whole always resisted this evil, even from her founding.
If you want to start complaining about slave-holding societies and "evil", I suggest you start complaining about the Islamic societies still stuck in the Dark Ages, trying to bring modern day slavery to us!
My point in bringing up slavery and the butchery of the Indians, and 38 million dead babies (and counting) in the United States was to cut off at the knees the ridiculous argument that America is "more moral" than Europe.
It is not true and it never has been true.
Both places have very black history.
Humans everywhere have very black history.
It is human nature to pitch headlong into evil whenever it gets the chance.
America is more prosperous and more powerful than Europe.
This is the reward of superior American financial and military acumen. It is not a reward for superior American morality. America's morality, as a nation, is just as hellishly black - every bit as black - as any nation's in Europe, Germany included.
My points were broad brush, and aimed at an equally broad brush claim of American national moral superiority. That was the point of the post. It was not to say "America: bad" on its own. It was to in response to "Europe: bad; America:good." No. Europe: bad. America: bad. Mankind: bad. Needing redemption.