班尼卡與傑弗遜的書信往來，暴露出傑弗遜提及奴隸問題的矛盾。

出處: Pendleton's Lithography. "Thomas Jefferson, Third President of the United States." Engraving after an original painting by Gilber Stuart, circa 1828. By Popular Demand: Portraits of the Presidents and First Ladies, 1789-Present, American Memory collections, Library of Congress.