A 1786 letter in which George Washington explains a ruse to return a runaway slave to his owner will be auctioned on Saturday.
Auctioneer Jim Smith said the reference to slavery increases the letter's value, and he predicted it will fetch at least $35,000 at the auction in Portsmouth, N.H.
"Obviously, the president had slaves, but you rarely see him mention them," Smith said. "It was not politically correct to talk about slaves."
However, Marli Weiner, a history professor at the University of Maine, said: "My sense is that people wrote about their business transactions all the time. In a private letter, I don't think that's so extraordinary."
In the three-page letter, Washington arranged to have his servants pick up some mules in Baltimore and bring them back to Mount Vernon. But one slave was headed to Baltimore for another reason, Washington told his friend James McHenry of Maryland, a future signer of the Constitution and secretary of war.
"One of the servant's that accompany's my Overseer, belongs to the honorable William Drayton of Charleston So.Ca.," Washington wrote.
"He goes to Baltimore under the impression of assisting in bringing the . . . Mules home but the real design of sending him there is to have him shipped for Charleston. I would beg of you, my good Sir . . . to have him shipped, and previously secured."
The slave ran away after Drayton visited Mount Vernon.