He entered Trinity College, Dublin, but left this institution without taking a degree, spending most of his time in the study of Hebrew, Sanscrit, and Gaelic. He was already a fine classical scholar, and contributed articles to French journals.

He began to take part in the repeal movement in 1843, but soon became dissatisfied with the methods of O'Connell, and was active in the party of which Smith O'Brien was the leader. The part that he took in the abortive rebellion of 1848 obliged him to leave the country, and he lived in France till 1854, when he came to the United States.

Here he published the "History of Ireland, by Geoffrey Keating, D. D., translated from the Original Gaelic, and Copiously Annotated" (New York, 1857). The mental strain to which O'Mahony was subjected in the preparation of this work, which brought him no pecuniary gain, affected his reason, and he was removed by his friends for a short time to a lunatic asylum.

The Fenian brotherhood, or Irish Republican brotherhood, was organized by him in 1860. The object of the association was to secure the freedom of Ireland. The name was probably derived from O'Mahony's Gaelic studies, the Fenians having been a military body in pagan Ireland, celebrated in the songs of Ossian. The organization of the new society was completed at conventions that were held in Chicago in 1864, and in Cincinnati in January, 1865. Its rapid growth in membership 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.

Many differences occurred between him and James Stephens, but he remained president of the organization for several years. The close of the civil war in the spring of 1865 gave a great impetus to the movement, owing to the number of Irish-American soldiers that were disbanded and anxious to see service elsewhere. Money poured into the Fenian exchequer; probably $500,000 was subscribed between 1860 and 1867.

O'Mahony did not take any part personally in the attempted insurrection in Ireland or in the raids on Canada, although his advice counted for much in these enterprises. He devoted the last years of his life to literary pursuits, but suffered from ill health and poverty. However visionary may have been his objects, he was honest, and although thousands had passed through his hands, he was often at a loss for a dollar. When his poverty was discovered he declined to receive assistance in any shape. Soon after his death his remains were taken to Ireland and interred with the honors of a public funeral in Glasnevin cemetery near Dublin.

O'MAHONY, John Francis, Fenian leader, born in Kilbeheny, County Cork, Ireland, in 1816; died in New York city, 7 February, 1877. He belonged to a family every generation of which, for the last 200 years, had been implicated in movements hosthe to English supremacy, and his father and uncle took part in the insurrection of 1798. He entered Trinity college, Dublin, but left this institution without taking a degree, spending most of his time in the study of Hebrew, Sanscrit, and Gaelic. He was already a fine classical scholar, and contributed articles to French journals. He began to take part in the repeal movement in 1843, but soon became dissatisfied with the methods of O'Connell, and was active in the party of which Smith O'Brien was the leader. The part that he took in the abortive rebellion of 1848 obliged him to leave the country, and he lived in France till 1854, when he came to the United States. Here he published the "History of Ireland, by Geoffrey Keating, D. D., translated from the Original Gaelic, and Copiously Annotated" (New York, 1857). The mental strain to which O'Mahony was subjected in the preparation of this work, which brought him no pecuniary gain, affected his reason, and he was removed by his friends for a short time to a lunatic asylum. The Fenian brotherhood, or Irish republican brotherhood, was organized by him in 1860. The object of the association was to secure the freedom of Ireland. The name was probably derived from O'Mahony's Gaelic studies, the Fenians having been a military body in pagan Ireland, celebrated in the songs of Ossian. The organization of the new society was completed at conventions that were held in Chicago in 1864, and in Cincinnati in January, 1865. Its rapid growth in membership 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. Many differences occurred between him and James Stephens, but he remained president of the organization for several years. The close of the civil war in the spring of 1865 gave a great impetus to the movement, owing to the number of Irish-American soldiers that were disbanded and anxious to see service elsewhere. Money poured into the Fenian exchequer" probably $500,000 was subscribed between 1860 and 1867. O'Mahony did not take any part personally in the attempted insurrection in Ireland or in the raids on Canada, although his advice counted for much in these enterprises. He devoted the last years of his life to literary pursuit, s, but suffered from ill health and poverty. However visionary may have been his objects, he was honest, and although thousands had passed through his hands, he was often at a loss for a dollar. When his poverty was discovered he declined to receive assistance in any shape. Soon after his death his remains were taken to Ireland and interred with the honors of a public funeral in Glasnevin cemetery near Dublin.