Previously known information on Thomas Dardis, brother of James (1766-1846) is that he was born in Ireland, was admitted to the Tennessee Bar in 1803, was elected to the Tennessee General Assembly from Knox County in 1807, was wounded in a duel with General John Cocke in 1808, and died from his wound ca. 1810. Ancestry.com records (U. S. Naturalization Records Indexes, 1794-1995) shows an entry for a Thomas Dardis on Oct. 3, 1801 (Record O. M. 1, p. 36 or 56).
This record was found in the NARA microfilm files (Roll M102, Cabinet 11A, Drawer 2) on May 18, 2011 and reads as follows: "Thomas Dardis a native of Ireland aged about 28 years now a resident of Washington County in the District of Columbia Labourer made oath that it was bona fide his intention to become a Citizen of the United States and to renounce and abjure all allegiance and fidelity to any foreign prince, potentate, State or Sovereignty whatsoever and particularly to the King of Great Britain to whom he was before a Subject." It is very likely, but not definitively proven, that this Thomas Dardis, b. ca. 1773, is James Dardis's brother.
The activities of a Thomas Dardis, a schoolteacher from Cappagh, Westmeath, in the Irish Rebellion of 1798, are mentioned in "Multyfarnham Parish History" by Peter Wallace (Westmeath Examiner Ltd., Mullingar, 1987). Cappagh the village just across the River Inny from Ballinalack, the known birthplace of James Dardis. The Rebel activity described was a battle with British infantry and Irish loyalist militia in the area of Granard, Streete, Ballinalack, Multyfarnham, and Crookedwood (Longford and Westmeath) on September 4 and 5, 1798. Again, there is no direct evidence that this is the same Thomas Dardis, but the home place and the apparent age and education of the rebel Thomas allow this to be the same person. And this Thomas, identified as a rebel, would have had to leave Ireland or be outlawed for life, and summarily hanged if captured.