William H. Casson at one time an active and leading member of the Putnam county bar but now living retired in Hennepin, was born in Brownsville, Pennsylvania, February 28, 1838, a son of Henry and Mary (Cock) Casson, both of whom were natives of England, the former born in 1807 and the latter in 1806. The father was a tailor by trade and after coming to the United States first located in Albany, New York. Subsequently, however, he removed to Pennsylvania and in 1848, when his son, William, was a youth of ten years, came to Hennepin, making the journey in accord with the slow stages of water travel. They sailed down the Monongahela river to Pittsburg and on the Ohio and Mississippi rivers to the mouth of the Illinois, proceeding then up stream to Hennepin. Henry Casson worked at his trade here for a few years, after which he became postmaster, acting in that capacity for a long period. About thirty years prior to his death, however, he retired from active life and made his home with his son, William, until he passed away at the venerable age of ninety-one years. His wife died in Hennepin in 1872. They were members of the Episcopalian church and Mr. Casson in ante bellum days was a stanch advocate of abolition principles, so that when the republican party was formed to prevent the further extension of slavery lie joined its ranks and remained one of its stalwart champions until his demise. His educational privileges in youth were limited to those of the common schools, but he became a well-informed man, reading broadly and thinking deeply. He was once a candidate for the state legislature. His family numbered eight children, but William and his brother, Henry, are the only ones now living. One child, who was born in England, died soon after coming to America. John R., deceased, was at one time circuit clerk of Vernon county, Wisconsin. Elizabeth B. became the wife of William Eddy and lived in Hennepin. Both are now deceased. Henry Casson, the surviving brother, is now sergeant-at-arms of the lower house of congress. His home was in Madison, Wisconsin, where he served as secretary to several governors and was recognized as a prominent factor in political circles.
William H. Casson acquired a common-school education in Brownsville, Pennsylvania, and in Hennepin, Illinois, subsequent to the removal of the family to this state when he was a youth of ten years. At the age of fourteen years he began working as a farm hand and a year later secured employment in a store, where he remained for a few years. He became an influential factor in local politics and at the age of twenty-four years was elected circuit clerk of the county, acting in that capacity for eight years, his duties being discharged with marked promptness and fidelity. While in that office he took up the study of law under the late Judge T. M. Shaw and was admitted to the bar in 1868. For many years he was one of the prominent representatives of the legal fraternity in Putnam county and served for sixteen years in the office of state's attorney. In 1867 he was chosen master in chancery and continued to fill that position until about a year ago. He is now living retired, his investments being sufficient to bring to him a good income.
In 1863 Mr. Casson was married to Miss Mary McMahon, who was born in Putnam county in 1842 and died February 19, 1904. She was a daughter of Owen and Margaret (Smith) McMahon, the former a native of Ireland and the latter of England. In the '30s they came to this country and for some years resided in Putnam county, Illinois. Unto Mr. and Mrs. Casson were born three children, but the youngest died in infancy. The daughter, Margaret Louise, is now the wife of Benjamin Robinson, professor of botany in Harvard University, and the son, Robert Owen, is engaged in the poultry business at Alexis, Illinois.
Mr. Casson is a stalwart republican and for many years has been prominent in politics in this county, wielding a wide influence in the councils of his party, his opinions often proving a decisive factor in the settlement of some contested question. His residence in Hennepin compasses the period of early pioneer development and of later progress. He can remember when people thought Chicago was so close to Hennepin that it would never amount to anything. Time and man have wrought many changes in the county and state during the six decades in which he has lived in Hennepin and Mr. Casson has performed his full share in the work of development and improvement. He was gifted by nature with strong mentality and keen discrimination, and the development of these latent powers and energies gained him place among the brilliant and able members of the bar of this part of the state. Now, however, he is living retired, owning and occupying one of the best homes in the city of Hennepin, while his realty possessions also include two hundred and fifty' acres of good farming land in Putnam county, from which he derives a substantial annual income.
Source: Past and Present of Marshall and Putnam Counties Illinois authored by John Spencer Burt and W. E. Hawthorne in 1907, page 318.