The following data is extracted from Illustrated History of the State of Idaho.
James O'Neill came to the northwest from the far-off Atlantic coast: nor have his travels been limited by his journey across the continent, for he spent some time among the mountains in the distant south. He was born in Rondout, New York, May 6, 1861 his parents being Patrick and Hannah (Mullroy) O'Neill, natives of Ireland. Both crossed the Atlantic to the United States in childhood, and were reared, educated and married in the Empire state. The father, who was a tanner by trade, died when our subject was only about five years old leaving the mother to care for her five small children. She lived to be fifty-five years of age and departed this life in Jarmyn, Pennsylvania.
When a mere lad of seven summers James O'Neill began to earn his own living in the coal breakers of Pennsylvania, receiving forty-two cents per day for his services. His youth was one of hard toil and his entire life has been one of diligence. In 1879 he left the east and went to the Black Hills, settling at Lead City, South Dakota, where he engaged in mining for a year.
He then went to Tombstone, Arizona, where he followed mining for a short time, after which he made his way to the Coeur d'Alene country on the discovery of the rich mineral deposits there. Later he was identified with mining interests at Butte, Montana, and thence went to Rocky Bar, Idaho, continuing his mining operations until November 3, 1896, when he was elected assessor of Elmore County and came to Mountain Home. Acceptably discharging the duties of that position, he won the public confidence, and in 1898 was elected sheriff of Elmore County.
While at Rocky Bar Mr. O'Neill was united in marriage, by Bishop Glorieux, to Miss Mary T. Donnelly, and to them have been born five children, namely: Anna Josephine, James Albert, Emmett John, Larkin Lucius and Allen Leo. The parents are both members in good standing of the Catholic Church, and Mr. O'Neill also belongs to the Ancient Order of United Workmen and Modern Woodmen of America. He is a good businessman, an efficient and faithful officer and a popular citizen. The difficulties and obstacles which beset his path in youth he has overcome by determined purpose, and his life demonstrates what is possible of accomplishment to those who in early life are deprived of favorable privileges and opportunities.
Source: Illustrated History of the State of Idaho