William Sydney Porter, writing as O. Henry, wrote in a dry, humorous style and, as in "The Gift of the Magi," often ironically used coincidences and surprise endings. Released from prison in 1902, Porter went to New York, his home and the setting of most of his fiction for the remainder of his life. Writing prodigiously, he went on to become a revered American writer.

(http://www.biography.com/people/william-sydney-porter-9542046#awesm=~oEJGdSOL0bHGoN)