Horatio Turpin (1755–1826) was the son of TJ’s aunt Mary Jefferson Turpin. During the Revolutionary War he served as an ensign in the 15th Virginia Regiment, 1777–78, and by 1781 he had become a captain in the militia. Turpin inherited over 1,500 acres in Buckingham and Powhatan counties, serving as sheriff of the latter beginning in 1807. In about 1821 he moved his large family to Kentucky, where he owned land as early as 1784 (Shackelford, Descendants description begins George Green Shackelford, ed., Collected Papers to Commemorate Fifty Years of the Monticello Association of the Descendants of Thomas Jefferson, 1965 description ends , 1:38; Turpin family Bible, in possession of his descendants in 1969, and Turpin Family Genealogical Notes [photocopies at Vi]; John H. Gwathmey, Historical Register of Virginians in the Revolution [1938], 786; Joseph T. McAllister, Virginia Militia in the Revolutionary War [1913], 80–1, 156; Turpin to TJ, 1 June 1807 [CSmH: JF] and Oct. 1823; Willard Rouse Jillson, Old Kentucky Entries and Deeds [1926], 156; Carl R. Bogardus, Gallatin County Estates: Wills, Administrations, Guardianships and Settlements, 1799–1838 [1985], 37–8).

Turpin also wrote to the State Department seeking to fill the vacant post of marshal for the district of Virginia. Andrew Moore was appointed on 10 Dec. 1810 (Turpin to Robert Smith, 8 Dec. 1810 [DNA: RG 59, LAR, 1809–17]; JEP description begins Journal of the Executive Proceedings of the Senate of the United States description ends , 2:156 [10, 11 Dec. 1810]).