O. Henry was the pseudonym of the American writer William Sydney Porter (September 11, 1862 – June 5, 1910). O. Henry's short stories are well known for their wit, wordplay, warm characterization and clever twist endings.
William Sidney Porter was born on September 11, 1862, in Greensboro, North Carolina. His middle name at birth was Sidney; he changed the spelling to Sydney in 1898. His parents were Dr. Algernon Sidney Porter (1825–1888), a physician, and Mary Jane Virginia Swaim Porter (1833–1865). They were married April 20, 1858. When William was three, his mother died from tuberculosis, and he and his father moved into the home of his maternal grandmother.
Porter graduated from his aunt Evelina Maria Porter's elementary school in 1876. His aunt continued to tutor him until he was fifteen. In 1879, he started working in his uncle's drugstore and in 1881, at the age of nineteen, he was licensed as a pharmacist.
Porter's most prolific writing period started in 1902, when he moved to New York City to be near his publishers. While there, he wrote 381 short stories. He wrote a story a week for over a year for the New York World Sunday Magazine. Porter married again in 1907, to childhood sweetheart Sarah (Sallie) Lindsey Coleman, whom he met again after revisiting his native state of North Carolina.
His health began to deteriorate in 1908, which affected his writing. Sarah left him in 1909, and Porter died on June 5, 1910, of cirrhosis of the liver, complications of diabetes and an enlarged heart.