Scrolling down, one sees an ad from none other than Thomas Jefferson:
> In Alberale, a Mulatto slave called Sandy, about 35 years of age, his stature is rather low, including to corpulence, and his complexion light; he is a shoemaker by trade, in which he uses his left hand principally, and is something of a horse jockey; ... Whoever conveys the said slave to me, in Albermarle, shall have 40 s. reward ...
One of the histories of the US that I read mentioned the ridicule that the British heaped on the Americans for their hypocrisy, a copy of the Declaration of Independence in one hand and a whip in the other.
It's striking to consider the self-delusion that must have been necessary for people at the time to believe in such wildly inconsistent notions as "inalienable rights" and slavery.
On the other hand, culture is a powerful reality distortion field. Scratch just a little below the surface and you'll find the most bizarre creatures scuttling for cover.