William Smith Newton was born on February 6, 1823, near the small town of Harmer, in Washington County, Ohio. The town, now part of Marietta, was located where the Muskingum River flows into the Ohio River, with Virginia (now West Virginia) located on the other side to the south. He was the son of Oren and Elizabeth Fuller Newton. His father, Oren, was an important figure in the community and was involved in farming and the grindstone industry. His grandparents were the early Marietta-area settlers Elias and Alice Stimson Newton.

In 1839 sixteen-year-old Newton enrolled in Marietta College’s Latin School, which was a preparatory school for younger students. After two years of study in the Latin School, in fall 1841 he advanced to the Marietta Academy, a preparatory school for the college. The following fall, Newton enrolled as a freshman at Marietta College. He completed his freshman year, 1842–1843, but he did not continue with courses or graduate from Marietta College.

Newton demonstrated an interest in medicine and learned from his cousin Robert Safford Newton, who practiced medicine in Gallipolis and was trained in the emerging field of eclectic medicine. Newton observed his cousin treating patients with eclectic methods, which influenced his decision to enroll as a medical student in fall 1843 at the Medical College of Ohio in Cincinnati. Newton graduated in 1845 from the Medical College of Ohio and returned to Harmar. Similar to an apprenticeship or residency, he began working alongside Seth Hart, a doctor in town. By 1850 Newton had his own medical practice in Harmar. In 1854 Newton and his family relocated to Ironton, Ohio. Newton was the eighth doctor in Ironton at that time. He had an active medical practice in downtown Ironton and frequently advertised in local newspapers.

On October 28, 1845, William married Frances Ann Hayward of Gallipolis. They had seven children during their marriage. Three of their children, Oren Hayward (1846–1858), Lewis Garland (May–October 1848), and Fanny Lillian (1857–1858), died before reaching adulthood. In 1862, when William enlisted in the Union Army, they had three children, Edward (Ned) Seymore (born 1850), Valentine Mott (born 1852), and Kate May (born 1860). Another child, John Beverly (born November 9, 1863), arrived during Newton’s military service.

Newton took immediate interest in serving the Union as a surgeon. In August 1862, volunteers from the counties of Adams, Scioto, Lawrence, Gallia, Jackson, and Pike organized at Ironton into five companies of the 91st Ohio Volunteer Infantry. Colonel John A. Turley from Scioto County commanded the regiment with Colonel Benjamin F. Coates second in command. The Army appointed George H. Carpenter as surgeon and John B. Warwick as assistant surgeon for the 91st. Newton received his official appointment as assistant surgeon for the regiment on September 17, 1862.

Newton served as assistant surgeon of the 91st Ohio Volunteer Infantry for most of the American Civil War, with only two exceptions. In October 1863 he became acting surgeon for the 2nd Virginia Cavalry and held that role until February 1864 when he returned to service as assistant surgeon of the 91st. Then, on March 18, 1865, he became surgeon of the 193rd Ohio Volunteer Infantry and kept that post until he mustered out with the regiment on August 9, 1865.

As assistant surgeon Newton managed several hospitals (both in seized buildings and in the field), tended to patients, ordered supplies, arranged for the wounded to return home, and informed families of the loss of a loved one. He quartered with officers in tents and houses, and was in close contact with other soldiers, many of whom he knew because of his medical practice.

Although a non-combatant, Newton was part of several significant military campaigns in West Virginia and Virginia. Following the Battle of Cloyd’s Mountain in May 1864, Confederates captured Newton and other medical staff, who were then asked to operate on wounded Confederate General Albert Gallatin Jenkins. The operation, amputation of the left arm, was successful, but Jenkins died after an attendant accidently knocked loose the ligature on a main artery. Thereafter, Newton and the other Union surgeons were sent to Libby Prison in Richmond. After three difficult days at Libby, the surgeons were released. Newton reported ill health due to the imprisonment, but he returned to active duty in July. By that time, the 91st was part of Union General Philip Sheridan’s summer campaign in the Shenandoah Valley. Following the Second Battle of Kernstown, Newton and others were dismissed from military service for allegedly straggling behind after the battle. Newton was quickly reinstated following confirmed reports that he had stayed behind in a safe location to avoid capture. Thereafter, Newton managed a large field hospital to care for the many wounded following the Battle of Opequan (Third Battle of Winchester) and the Battle of Cedar Creek.

By 1865, Newton prepared to return to Ohio as a farmer. On August 9, 1865, he mustered out of the Union Army after three years and four months of service. Instead of becoming a farmer, Newton moved to Gallipolis, opened a medical practice, and served as postmaster from 1867-1875. In 1880, Newton secured an invalid pension. He cited that his capture and brief imprisonment after the Battle of Cloyd’s Mountain in 1864 led to his poor health. In mid-November 1882 Newton fell ill from stomach pains. In addition to liver damage, he suffered from ulcers and other internal ailments caused by his wartime service. Newton died on Saturday, November 18, 1882, just a few months shy of his sixtieth birthday. He was buried in the Pine Street Cemetery in Gallipolis.