270. THOMAS JEFFERSON Beautiful, nice association franking signature "free Th. Jefferson", penned at the top left of a cover addressed in his hand to: "Doctr. Richard Harlan Philadelphia". Harlan (1796-1843) was a prominent anatomist and paleontologist who provided Jefferson with fossil specimens for his collection which was compiled to advance the cause of American science. According to the American Academy of Natural Sciences, "Harlan worked extensively on Cretaceous marine reptiles and Cenozoic mammals, including such well know taxa as Mosasaurus and Basilosaurus . He also published a major work on American mammals (Fauna Americana, 1825) and studied some of Jefferson's fossils from Big Bone Lick". Backed by graph paper, two small holes at folds at bottom, well clear of text, overall very good condition. $5,000 - 6,000