William Sydney Porter, better known by his favorite pseudonym, O Henry, served three years at the Ohio State Penitentiary for embezzling money from the First National Bank of Austin.
Sentenced to five years in prison, O Henry proved a model inmate. He did not earn a single demerit on his prison record, and his sentence was reduced by a full two years thanks to his good behavior.
Given O Henry's immense shame regarding his criminal past, he never sought a presidential pardon on his own behalf--even though he'd likely have gotten it.
He remains one of the greatest authors of short fiction in the English language. The annual American awards for short fiction is named in his honor, The O. Henry Prizes.