Sally Hemings was the daughter of Jefferson’s father-in-law and a slave, which, of course, made her the half sister of Jefferson’s wife. The accounts we have suggest that Hemings and her half sister looked very similar. Jefferson and Hemings had children that could pass for white. But, for all of the remarkable biological similarities between Jefferson’s legitimate and illegitimate families, they had a completely different status under the laws of Virginia. One group of children was free; the other was not.
Did the absurdity of this ever occur to Jefferson? You would certainly hope so.