"Thomas Francis Meagher (1823-1867) was an Irish revolutionary, flamboyant orator, and Union veteran of the Civil War who twice served as acting governor of Montana Territory. Exiled from the British Isles to a penal colony in Tasmania in 1848, this Irish freedom fighter soon escaped to New York City. Arriving in Montana in 1865 at the height of its gold rush, Meagher served as acting territorial governor in 1865-66 and 1866-67. His political terms are viewed by many as opportunistic and corrupt. Meagher's mysterious disappearance from a steamboat in 1867 has led to disparate theories about the cause of his death - from falling into the Missouri River while intoxicated to premediated murder by British agents."
"More than for any direct contribution to Montana, Thomas Francis Meagher owes his place on the Capitol grounds to his Irish Catholic heritage and Irish nationalist politics. Protestant Irish, or "Orangemen," led Helena's 1894 bid for the capital, while Irish Catholics led by copper magnate Marcus Daly favored Anaconda. Though Helena won the capital fight, in 1905 Anaconda backers settled the score. The Meagher Memorial Association raised twenty thousand dollars by public subscription for the statue by Irish-born Chicago sculptor Charles J. Mulligan (1866-1916). On July 4, 1905, speakers extolled Meagher's love of liberty and Irish heritage as his statue was dedicated before a crowd of over fifteen hundred." p. 80
Reference: Montana's State Capitol - The People's House by Kirby Lambert, Patricia M. Burnham and Susan R. Near. This book is available from the Montana Historical Society