Think about Lincoln's Gettysburg address for a minute.

...conceived in Liberty, and dedicated to the proposition that all men are created equal...

Which is a big fat lie. True only if you were a white male landowner.

If the union has not been founded on slavery then there wouldn't even have been a civil war to win/lose.

The founding fathers as a group were quite happy with slavery, racism, and sexism.

That's what the USA was founded on, that is the legacy it maintains today.