It's not as simple as you make out.
"slavery as an institution, is a moral and political evil in any country."
Robert E. Lee
Not that Lee never owned slaves, because he did and thought that they were better here then in Africa until they could be "civilized "
Lincoln wanted to free the slaves but not at expensive of the Union.
The war for the south was about states rights and at that time slavery was a really big part of states rights.
For the north the war was about preserving the union and the raw materials from the south.
So even the battle flag of Virginia can have more than one meaning depending on who is looking at it.
For some it represents the courgette of their ancestors.
Pickett's charge.
And for others it only represent a very sad time in the history of the country.
As far as flags this saw more slaves then the US.
Robert E. Lee was one person. The views expressed in that one quote weren't exactly typical at the time among Confederate politicians. Look at what Jefferson Davis said or Alexander Stephens.
But I'm not a founding father apologist. They were racist pieces of shit (just not as shitty as the Confederates) and aren't anywhere close to deserving of the deity status some people want to bestow on them.