A native of Beaver county, Pennsylvania, he was born on the 2d of June, 1824, a son of James and Mary (Sloan) Warnock, both likewise natives of the Keystone state. The father died when our subject was but six years of age, leaving his widow with a family of six children. William S. Warnock went to live with an aunt in Ohio and was there reared and educated, attending school at Lowell and Salem, that state. He desired to become a lawyer and began his legal study in the office of S. W. Gilson, of Canfield, Ohio, and in 1853 was admitted to the bar. He began the practice of his profession in Lowell but subsequently removed to Canfield, where he remained until 1855. In that year he came west as he was in poor health and his physicians advised a change of climate. He made the journey by rail to Cleveland, thence by water to Detroit and then by rail to Davenport by way of Chicago. He visited Iowa City and Des Moines, which was then but a small village and located at Chariton, this state, although he had intended to go as far as the mountains. He taught a select school during the summer and fall of 1855 and then removed to Pleasanton, Decatur County, where for two years he practiced law. He was then for a like period of time engaged in the mercantile business in Davis City, being one of the first merchants of that town. He returned to Pleasanton, where he resided until 1872, when he again moved to Davis City and became a member of the firm of Bowman & Warnock, who successfully conducted a general mercantile store. In the fall of 1878 he was elected to the state legislature and he proved an efficient member of the Seventeenth General Assembly. On the expiration of his term he removed to a fine farm of three hundred acres, Burrell Township, where he devoted his attention to stock-raising during the remainder of his life. Mr. Warnock was married on the 2d of October, 1856, to Miss Sarah Davis, a daughter of William and Elizabeth (Van Meter) Davis, natives of Highland county, Ohio. Mr. Warnock was a democrat and fraternally belonged to Remembrance Lodge, No. 375, A. F. & A. M., at Davis City and Lamoni Chapter, No. 33, R. A. M. He was liberal in his religious views. Throughout his life he was guided by the same public spirit that prompted him to enlist in the Civil war on the 2d of June, 1864. He was a member of Company C, Forty-eighth Iowa Infantry, and served until October 21st of that year, his regiment being on guard duty at Rock Island the greater part of the time.