O. Henry was born William Sydney Porter on September 11, 1862, in Greensboro, North Carolina. Though his father, Algernon Porter, was a doctor, the young boy did not receive much formal education. As a teenager, he worked as a pharmacist's assistant in his uncle's drugstore to help support his family. At 19, worried that he might be susceptible to the pneumonia that had killed his mother at a young age, he moved to Texas to take advantage of its warm, dry climate, There he worked on a cattle ranch owned by friends of his family. These early jobs—pharmacist, ranch hand, and bank teller—gave him plenty of material for his stories about poor, working-class people.

When he was twenty-two, Porter moved to Austin, where he landed a job as a bank teller. He also met Athol Estes, who soon became his wife; together they had a daughter, Margaret...