William H. Dupuy was born around 1836 in Prince Edward County, Virginia, to James Dupuy. His father was a merchant who owned $200 of real estate in 1850. His father died around 1855. Dupuy moved to Arkansas around 1857, purchasing 40 acres of land. By 1860, he was working as a merchant, and he owned $1,500 of real estate and $15,000 of personal property. He enlisted in the Confederate army on June 23, 1862, and mustered in a 1st lieutenant in Crawford’s Arkansas Infantry Battalion. According to his service records, he was 5 feet, 7½ inches tall, with dark hair and dark eyes. He was captured near Arkansas Point, Arkansas, on January 11, 1863, and Union officials sent him to Camp Chase in Ohio. He remained there until April 1863, when he was exchanged and returned to his regiment. He died sometime after 1863.