Thomas Jefferson - Paleontologist 

I propose adding Paleontologist to the Categories. From the Wikipedia article, Vertebrate paleontology:

Thomas Jefferson is credited with initiating the science of vertebrate paleontology in the United States with the reading of a paper to the American Philosophical Society in Philadelphia in 1797. Jefferson presented fossil bones of a ground sloth found in a cave in western Virginia and named the genus (Megalonyx). The species was ultimately named Megalonyx jeffersonii in his honor.Jefferson, Thomas, "A Memoir on the Discovery of Certain Bones of a Quadruped of the Clawed Kind in the Western Parts of Virginia", Read before the American Philosophical Society, March 10, 1797. The "certain bones" consisted of three large claws and associated smaller bones. He theorized that they were the remains of an extinct lion which he named Megalonyx ("giant claw"). In 1799, Dr. Caspar Wistar correctly identified the remains as belonging to a giant ground sloth. In 1822 Wistar officially named it Megalonyx jeffersonii.Jefferson, Thomas (1799), "A Memoir on the Discovery of Certain Bones of a Quadruped of the Clawed Kind in the Western Parts of Virginia", Transactions of the American Philosophical Society, Vol. 4 pp. 246-260.Wistar, Caspar (1799), "A Description of the Bones Deposited, by the President, in the Museum of the Society, and Represented in the Annexed Plates", Transactions, pp. 526-531, plates. Jefferson corresponded with Cuvier, including sending him a shipment of highly desirable bones of the American mastodon and the woolly mammoth.Rice, Howard C, Jr., "Jefferson's Gift of Fossils to the Museum of Natural History in Paris," Proceeding of the American Philosophical Society, 95 (1958): 597-627.

He also carried on a well known lively debate and correspondence with Buffon, and engaged others, including Lewis and Clark, to procure specimens for study. He is just as much the Father of American Paleontology as he is the Father of American Architecture, neither for which is he primarily known, nor from which he deign make a livelihood. If cryptographer made the cut, I'm just sayin...