John Mitchell Mason (1770–1829), clergyman and educator, was born in New York City and graduated from Columbia College (later Columbia University) in 1789. He afterwards studied theology with his father and at the University of Edinburgh, returning to New York in 1792 in order to succeed his father as pastor of an Associate Reformed congregation there. Mason held this post until 1810, then established a new congregation with a larger church building and officiated there until 1821. In 1800 he published a pamphlet accusing TJ of being an “infidel” and warning against his presidential election. Mason founded an Associate Reformed theological seminary in New York, at which he held a professorship, 1805–16, and he also edited the Christian’s Magazine, 1806–11. He served as a trustee of Columbia College, 1795–1821, and as provost, 1811–16. In 1821 Mason moved to Carlisle, Pennsylvania, to assume the presidency of Dickinson College. In the following year he transferred his allegiance to the Presbyterians. Mason resigned from Dickinson in 1824 and returned permanently to New York City (DAB description begins Allen Johnson and Dumas Malone, eds., Dictionary of American Biography, 1928–36, repr. 1968, 20 vols. in 10 description ends ; Ebenezer Mason, ed., The Complete Works of John M. Mason, D.D., 4 vols. [1832]; Jacob Van Vechten, Memoirs of John M. Mason, D.D., S.T.P. with portions of his correspondence [1856]; Sprague, American Pulpit description begins William B. Sprague, Annals of the American Pulpit, 1857–69, 9 vols. description ends , 4:1–26; Thomas, Columbia University Officers and Alumni description begins Milton Halsey Thomas, Columbia University Officers and Alumni, 1754–1857, 1936 description ends , 4, 73, 112; A Catalogue of the Graduates in the faculties of Arts, Divinity, and Law, of the University of Edinburgh, since its foundation [1858], 215; [Mason], The Voice of Warning, to Christians, on the Ensuing Election of a President of the United States [New York, 1800]; Joshua A. Lippincott and Ovando B. Super, Alumni Record of Dickinson College, Carlisle, Pa. [1886], xv–xvi; New York Commercial Advertiser, 28 Dec. 1829).

TJ had received a copy of Mason’s Address, delivered at the organization of the faculty of Dickinson College, January, 15th, 1822 (Carlisle, 1822; Poor, Jefferson’s Library description begins Nathaniel P. Poor, Catalogue. President Jefferson’s Library, 1829 description ends , 6 [no. 226]; TJ’s copy in DLC: Rare Book and Special Collections), which spoke to the school’s trustees and auditors on the occasion of the dormant institution’s revival; defined the three objectives of education as “the evolution of faculty, the formation of habits, and the cultivation of manners” (p. 2); and suggested that achieving these goals depended on the college’s government “being reasonable, being firm, and being uniform” (p. 14).