Hugh Williamson (1735–1819), physician, public official, and author, was a native of West Nottingham, Chester County, Pennsylvania. He studied theology after graduating in 1757 from the College of Philadelphia (later the University of Pennsylvania) and was licensed to preach by the Presbytery of Philadelphia. Williamson soon changed professions. He taught mathematics at his alma mater, 1760–63, studied in London and Edinburgh beginning in 1764, and received an M.D. from the University of Utrecht. Williamson then practiced medicine in Philadelphia before moving in 1777 to Charleston, South Carolina, and shortly thereafter to Edenton, North Carolina, where he kept a medical practice and engaged in trade with the French West Indies. During the Revolutionary War he served as surgeon general for the North Carolina militia, 1780–81. Williamson was a delegate in the North Carolina House of Commons in 1782 and 1785. He represented that state in the Continental Congress, 1782–85 and 1787–88; the 1787 Philadelphia Convention, where he signed the new United States Constitution; and the United States House of Representatives, 1790–93. Already a member of the American Philosophical Society when he moved to New York City in 1793, Williamson became a founder of the Literary and Philosophical Society of New-York and a member of the New-York Historical Society and New York City’s Humane Society. He published Observations on the Climate in Different Parts of America (New York, 1811), The History of North Carolina, 2 vols. (Philadelphia, 1812), and other books and essays on medical, political, and scientific topics. After his death TJ attested to Williamson’s erudition and usefulness to the public (ANB description begins John A. Garraty and Mark C. Carnes, eds., American National Biography, 1999, 24 vols. description ends ; DAB description begins Allen Johnson and Dumas Malone, eds., Dictionary of American Biography, 1928–36, 20 vols. description ends ; David Hosack, A Biographical Memoir of Hugh Williamson, M.D. LL.D. [New York, 1820; Poor, Jefferson’s Library description begins Nathaniel P. Poor, Catalogue. President Jefferson’s Library, 1829 description ends , 5 (no. 165)], esp. 31–2, 67; Louis W. Potts, “Hugh Williamson: The Poor Man’s Franklin and the National Domain,” North Carolina Historical Review 64 [1987]: 371–93; Samuel A. Ashe, ed., Biographical History of North Carolina [1906], 5:458–66; Literary and Philosophical Society of New-York, Transactions 1 [1815]: v–vii, xv–xvi; APS description begins American Philosophical Society description ends , Minutes, 2 Feb. 1768 [MS in PPAmP]; PTJ description begins Julian P. Boyd, Charles T. Cullen, John Catanzariti, Barbara B. Oberg, and others, eds., The Papers of Thomas Jefferson, 1950– , 37 vols. description ends , esp. 7:569–70; New-York Evening Post, 24 May 1819).

Samuel Latham Mitchill (1764–1831), physician, educator, and public official, was born in Hempstead, New York. After serving a medical apprenticeship in New York City, 1781–83, he enrolled at the University of Edinburgh, receiving an M.D. in 1786. Mitchill was a professor of natural history, chemistry, and agriculture at Columbia College (later University), 1792–1801; professor successively of chemistry, natural history, and materia medica at the College of Physicans and Surgeons (later merged with Columbia University), 1807–26; and vice president of Rutgers Medical College (in New York City), 1826–30. He served three terms in the New York state legislature, 1792, 1798, and 1810, and he represented New York as a Jeffersonian Republican in the United States House of Representatives, 1801–04 and 1810–13, and the United States Senate, 1804–09. A member of the American Philosophical Society, Mitchill was a founder of the Literary and Philosophical Society of New-York, the New-York Institution for the Instruction of the Deaf and Dumb, and the Lyceum of Natural History in the City of New York (later the New York Academy of Sciences), and a president of the Society for the Promotion of Agricultural Arts and Manufactures of New York and the American Mineralogical Society. He was a founder in 1797 and longtime editor of the Medical Repository, a pioneering New York medical and scientific journal, and he authored numerous articles, orations, and books on scientific, cultural, and political topics, several of which TJ owned. Mitchill’s A Discourse on the Character and Services of Thomas Jefferson, more especially as a Promoter of Natural and Physical Science (1826) was based on his 11 Oct. 1826 address to the Lyceum of Natural History (ANB description begins John A. Garraty and Mark C. Carnes, eds., American National Biography, 1999, 24 vols. description ends ; DAB description begins Allen Johnson and Dumas Malone, eds., Dictionary of American Biography, 1928–36, 20 vols. description ends ; Alan David Aberbach, In Search of An American Identity: Samuel Latham Mitchill, Jeffersonian Nationalist [1988]; Mitchill, Some of the Memorable Events and Occurrences in the Life of Samuel L. Mitchill, of New-York, from the Year 1786 to 1826 [ca. 1828]; “Dr. Mitchill’s Letters from Washington: 1801–1813,” Harper’s New Monthly Magazine 58 [1879]: 740–55; APS description begins American Philosophical Society description ends , Minutes, 21 Jan. 1791 [MS in PPAmP]; Literary and Philosophical Society of New-York, Transactions 1 [1815]: v–vii, xv–xvi; Directors of the New-York Institution for the Instruction of the Deaf and Dumb, Annual Report 25 [1844]: 13–8; Herman Le Roy Fairchild, A History of the New York Academy of Sciences, formerly the Lyceum of Natural History [1887], 52, 57–62; PTJ description begins Julian P. Boyd, Charles T. Cullen, John Catanzariti, Barbara B. Oberg, and others, eds., The Papers of Thomas Jefferson, 1950– , 37 vols. description ends , esp. 32:18–9; Sowerby, description begins E. Millicent Sowerby, comp., Catalogue of the Library of Thomas Jefferson, 1952–59, 5 vols. description ends nos. 670, 977, 4006; New-York Spectator, 9, 13 Sept. 1831).