Throughout my history of ideas travel series following Thomas Jefferson, slavery was on my mind a lot: the institution as a whole, and Jefferson’s relationship to it. I was reminded of it constantly: by an original book from his own collection titled ‘The Horrors of Slavery’ now in the Library of Congress, which also displays a slave sale contract between himself and James Madison from 1809; the slave quarters and artifacts at Monticello; museum displays and plaques in D.C., Williamsburg, and Philly; and signs telling the story of his brief but telling correspondence with Benjamin Banneker.

As every student of American history learns early on, Jefferson’s words in the Declaration of Independence and his stated beliefs contrast sharply with his life as a slaveowner. And nearly every place I find something written about Jefferson, this contradiction is addressed but never really resolved.

Jefferson was in favor of the abolition of slavery…