American writer O. Henry was born William S. Porter in Greensboro, N.C., on Sept. 11, 1862. The forever commemorative stamp honoring him (Scott 4705) was issued exactly 150 years after his birth, on Sept. 11, 2012.

The United States Postal Service printed biographical information about the author on the back of the pane of stamps celebrating him.

“Nobody wrote surprise endings like O. Henry, who specialized in short stories with a final unexpected twist … His tales, such as ‘The Gif of the Magi’ and ‘The Ransom of Red Chief,’ are remembered for their jaunty tone and rich irony.”

A talented artist, Porter worked as a draftsman and a bank teller, but was found guilty of embezzlement in 1898 and spent three years in an Ohio penitentiary.

Released in 1901, he began writing the short stories that would eventually bring him great fame.

“O. Henry wrote nearly 300 stories,” the Postal Service notes, “most of them in the final eight years of his life. By the time of his death, he was the most widely read storyteller in America and was internationally admired—perhaps the greatest surprise ending of all.”