In Hiroshima....we ended the war with Japan a whole hell of a 
lot earlier than if we had invaded.  Once we bombed them, the Japanese
government surrendered, because unlike Saddam, they actually cared
about their citizenry.  It was terrible that nukes were dropped on 
so many civilians, but it was war that Japan started with us and dropping
those nukes was better than tens of thousands of American GIs dying
during an invasion of Japan.

What happened when we enslaved African and brought them here as slaves..
Do mean the ones we bought from other Africans?  Was slavery horrible, yes.
Was it wrong? Yes.  Are the black ancestors of slaves living in America 
today WAY, WAY, WAY better off than if the were living in Africa?  YES!

...and what happened when we killed the native people who lived here before
us?  Okay, you have got a great point here.  I don't diagree and frankly, 
I think that if any group in America has a right to complain, its
the American Indian.  My wife's from Oklahoma and she has told me about
the reservations out there.