Meagher, Thomas Francis (mär) [key], 1823–67, Irish revolutionary and Union general in the American Civil War, b. Waterford, Ireland. A leader of the Young Ireland movement, he was arrested and condemned to death for his part in the abortive rebellion of 1848, but the sentence was commuted to penal servitude in Van Diemen's Land (now Tasmania). Escaping, he went to New York City in 1852, practiced law, and edited the Irish News. In the Civil War, Meagher fought at the first battle of Bull Run with the famous 69th Regiment and organized (1861–62) the Irish Brigade of New York. His brigade was eventually decimated in fighting with the Army of the Potomac from the Peninsular campaign through Chancellorsville, and Meagher resigned (1863) as brigadier general of volunteers. His resignation was soon canceled, and at the end of the war he was serving under General Sherman. He was appointed secretary of Montana Territory in 1865 and served as temporary governor, but his rule was unpopular. He drowned in the Missouri River near Fort Benton while awaiting a shipment of weapons for the Montana militia. His Speeches on the Legislative Independence of Ireland was published in 1853.
See biography by R. G. Athearn (1949); P. J. Jones, The Irish Brigade (1969).