Thomas Addis Emmet (1764–1827), attorney and Irish patriot, was born in County Cork, Ireland. He received a B.A. in 1783 from Trinity College, Dublin, and he took a medical degree the following year at the University of Edinburgh. After practicing medicine for a few years, Emmet decided to become a lawyer. Called to the Irish bar in 1790, he quickly earned a reputation as a formidable barrister and an ardent Irish nationalist. Emmet joined the United Irishmen, soon became the society’s secretary, and was one of its directors by 1797. He was imprisoned by the British authorities, 1798–1802, and then exiled in consequence of his support for Irish independence. Having spent a short time on the European mainland, Emmet immigrated to New York in 1804. With important initial assistance from George Clinton and DeWitt Clinton, he made a name for himself within the American legal establishment. During his long career Emmet argued a number of cases before the United States Supreme Court, most famously Gibbons v. Ogden (1824), in which he unsuccessfully maintained the constitutionality of a New York law granting Robert Fulton and Robert R. Livingston a thirty-year monopoly on steamboat traffic in the state. Although Emmet largely eschewed politics after his arrival in the United States, he lost a bid as a Republican for a seat in the New York legislature in 1812, and he served as state attorney general, 1812–13. Emmet met TJ in Washington shortly after his arrival in America (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 ; DNB description begins Leslie Stephen and Sidney Lee, eds., Dictionary of National Biography, 1885–1901, 22 vols. description ends ; ODNB description begins H. C. G. Matthew and Brian Harrison, eds., Oxford Dictionary of National Biography, 2004, 60 vols. description ends ; Charles Glidden Haines, Memoir of Thomas Addis Emmet [1829]; George Dames Burtchaell and Thomas Ulick Sadleir, eds., Alumni Dublinenses: A Register of the Students, Graduates, Professors and Provosts of Trinity College in the University of Dublin (1593–1860) [1935], 264; Joel Barlow to TJ, 20 Aug. 1804 [DLC]; John Hollins to TJ, 14 Dec. 1804 [MHi]; New York Mercantile Advertiser, 16 Apr. 1805; New York Columbian, 18 Apr. 1812; New York Commercial Advertiser, 15 Aug. 1812; New York Public Advertiser, 19 Feb. 1813; Marshall, Papers description begins Herbert A. Johnson, Charles T. Cullen, Charles F. Hobson, and others, eds., The Papers of John Marshall, 1974–2006, 12 vols. description ends , 8:67, 10:7, 10–1; New-York Spectator, 16, 20 Nov. 1827).

John Franklin Dumoulin (ca. 1792–1825), attorney, was a native of Dublin who attended school in Portarlington, Queen’s County (later County Laoighis), Ireland, before earning a B.A. in 1810 from Trinity College, Dublin. He qualified for the bar in Ireland before immigrating to the United States in 1815. By 1817 Dumoulin had settled in New Orleans, where he practiced law and befriended the extended Trist family. A member of the Hibernian Society of New-Orleans who served as that organization’s secretary in 1819, Dumoulin became a naturalized American citizen in 1821. He died in New Orleans (John Cook Wyllie, “The Jefferson-Randolph Copies of an Anonymous Work Entered Three Ways by Sabin,” VMHB description begins Virginia Magazine of History and Biography, 1893–  description ends 56 [1948]: 80–3; Burtchaell and Sadleir, Alumni Dublinenses, 249; NcU: NPT; Orleans Gazette and Commercial Advertiser, 4 Mar. 1819; Louis Moreau Lislet, A General Digest of the Acts of the Legislature of Louisiana: Passed from the Year 1804, to 1827, Inclusive [1828], 2:408–9; Dumoulin’s naturalization record, 30 July 1821 [TxFNA: RG 21, RUSDCEDL, Minute Book, 5:148–9]; New Orleans Louisiana Gazette, 5 Aug. 1825; New Orleans Louisiana State Gazette, 16 Nov. 1825; New Orleans Louisiana Advertiser, 17 Oct. 1826).