He was the youngest son of William Sweeny of Dunmanway, in the county of Cork, of whom it is said that he “was a true Celt, gifted with uncommon force of character, and not less remarkable for his courage, daring, and manly spirit than for that nice sense of honor that ever distinguishes ‘the noblest work of God, an honest man.’” He died in 1827 and was buried at Macroom, Cork, where numerous generations of the family are interred. The branch of the family from which Gen. Thomas William Sweeny, the subject of this sketch, was descended, has been located in the county of Cork since the thirteenth century, having migrated thither from Donegal, in the north of Ireland. Of the parent stock, Dr. McDermott states that “it was itself a branch of the O’Neills which settled in Donegal and founded three great families, namely: MacSweeny of Fanad, who had extensive territories west of Lough Swilly, and whose castle was at Rathmullen; MacSweeny of Banagh, who had a castle at Rathain, and MacSweeny na D’Tuatha, signifying MacSweeny of the Territories.” According to O’Brien and other authorities he was called MacSweeny na D’Tuagh, signifying MacSweeny of the Battle Axes, a title said to have been derived from their having been standard bearers and chiefs of gallowglasses to the O’Donnells. It is from the latter MacSweeny that the subject of our sketch was descended. Dr. Smith, in his History of the County of Cork, states that “the MacSweenys had the parish of Kilmurry, in the territory of Muskery, county of Cork, and their chief castle at Cloghda, near Macroom, and had also Castlemore, in the parish of Moviddy.” He likewise mentions that “they were anciently famous for Irish hospitality,” and relates “that one of the family erected a large stone near the castle of Cloghda, inviting all passengers to repair to the house of Edmund MacSweeny for entertainment.” John O’Mahony, the distinguished Irish scholar, author of the standard translation of Keating’s History of Ireland, says: “The MacSweenys were standard bearers and marshals of the O’Donnells. They were famous throughout Ireland as leaders of those heavy-armed soldiers called gallowglasses. A branch of the family settled in the county of Cork in the thirteenth century, as commanders of those soldiers under the McCarthys of Desmond.” On the passage to the United States, with his mother and brother William, in 1832, Thomas W. Sweeny, the subject of this sketch, was swept overboard from the ship _Augusta_, by a huge wave, and narrowly escaped drowning, being rescued by three members of the crew who put off in a boat. He had been in the water thirty-five minutes. After finishing his education in the schools of New York city, young Sweeny was apprenticed to the printing business in the well known firm of Gould, Banks & Company (now, 1899, Banks & Brother), at that time the leading law book publishers of the United States, “where his many good qualities made him a general favorite.”