Born at Montville, Geauga County, Ohio, August 7, 1833, where he lived until he was twelve years of age, when he removed with his parents, Jonas and Mary Underwood, to McHenry County, Illinois. His literary education was received in common schools at Mount Morris. He began the study of medicine with Dr. Hager, of Marengo, Illinois, in 1855, and continued his studies with Dr. Miller, of the same place. He then entered the office of Dr. J. W. Green, also of Marengo, and also attended three full courses of lectures at Rush Medical College, Chicago, graduating there from, February 14, 1859. In May following he came to Hardin county, and located at Steamboat Rock, in the practice of his profession. He remained at that place until July, 1860, when he removed to Eldora. In a short time he secured a fine practice, but when the war commenced he considered that it was his duty to be in the field, and therefore offered his professional services. He was commissioned as Assistant Surgeon of the 12th Iowa Infantry, and went with the boys to the front, serving until final discharge, in October, 1865. From the spring of 1863 till the close of the service he acted as Surgeon of the regiment. On his discharge he returned to Eldora, and resumed the practice of his profession. He was elected to represent Hardin County as a senator in the Twenty-first Iowa General Assembly, 1886. As a citizen he is enterprising, and ever ready to do all in his power to advance the interests of his town and county. Dr. Underwood was united in marriage, in 1861, with Sophia A Ellis, who located in this county in 1856.