This is silly. Most white Americans were not here before 1865. And almost none were slave owners. Most “black” people have white DNA. And one question nobody asked, if someone was a slave in Africa were you better off when you arrived in America even as a slave?
If you go and read the numbers something like 97% of usa whites never owned slaves at any time.
In addition, there were many free blacks in the south before the Civil War who were slaveholders.