was he part of any war?
Yes, US Civil War.
John O'Mahony
At the time of the Cincinnati convention, O'Mahony held the rank of colonel of the 69th Regiment of New York State Militia, recruited mainly from the ranks of the Brotherhood, which had also furnished a large proportion of Meagher's Irish Brigade, the Corcoran Legion, and Irish regiments engaged in the US Civil War.
who started rogers locomotive and machine works? Thomas Rogers, Morris Ketchum and Jasper Grosvenor. when? 1832 where was this company started? 1856 does the company still exist? No do you know when it closed down? 1920s why did it close down? Stiff competition and an inability to increase its own capacity. did another company take over or merge with them? ALCO purchased it but sold off later, now the building is home of Paterson Museum. where is the museum located? Paterson, in Passaic County, New Jersey. what items are kept in here? Fenian Ram, archive of Holland's life and work, etc. is there any memorabilia of the trains kept? Yes the first item that you mentioned that is kept in the museum, what is it? Submarine for whom did he build it? For use by the Fenian Brotherhood. who are they? An Irish republican organization. who founded them? John O'Mahony and Michael Doheny. where was the first person born? Kilbeheny, County Limerick, Ireland. what was his profession? Gaelic scholar.
wiki:10832388
John O'Mahony [SEP] Civil War
At the time of the Cincinnati convention, O'Mahony held the rank of colonel of the 69th Regiment of New York State Militia, recruited mainly from the ranks of the Brotherhood, which had also furnished a large proportion of Meagher's Irish Brigade, the Corcoran Legion, and Irish regiments engaged in the US Civil War. The rapid growth in membership of the Fenian Brotherhood rendered it impossible for O'Mahony to retain the colonelcy of the 69th regiment, which he had held for some time, and resigning he gave all his attention to the spread of Fenianism.