Andrew Jackson's family had recently come to the colonies--it's not likely he had any black ancestors in Scotland or Ireland. There was a rumor about one of Harding's ancestors having black ancestry, but that may have been made up by a neighbor who didn't like the man. Jefferson was born in 1743, just decades after African slaves started to become numerous in Virginia--if any of his grandparents or great-grandparents had been black he probably would have looked like someone of mixed-race ancestry.
Supposedly all modern-day humans are descended from African ancestors (the "out of Africa" theory). Anyway the Garden of Eden was in Africa. I learned that from one of my classmates in high school. The Bible says that Adam named all the animals, so the Garden of Eden had to be in Africa for him to name the lion.
Lol! If you listen to some people, all of our ancestors were gay as well.
Even taking a literalist approach to the Garden of Eden, the range of various lion species was far greater in the past then it stands currently. There were lions in Europe and the New World, as well as Asia (there are still Asian lions, though they have a limited range). And that is assuming a rather strict definition of lion - I doubt that current taxonomic classifications was used in the Bible.