Slavery was abolished well before that.
"And then, starting in 1973, began the wholesale massacre of innocent babies: 38 million and counting. America is an evil country, with a soul as black as hell."
Abortion is truly an evil act. But a "country" isn't evil. There are people who are opposed to and fight against abortion here and now just as there were those that fought against other evils in our nations history. And our success would come sooner if it weren't for the import of socialism.
But if there were some sort of scale of moral balance you are right in that abortion weighs America down with those horrors of Europe's past. Perhaps the newly liberated former republics of Russia will show us all the way out of darkness.
Slavery was abolished in 1865, but American apartheid was not abolished until 1964.