Question: Who came up with the joke why did the chicken cross the road?
Disambiguated questions and answers: question: Who came up with the riddle why did the chicken cross the road?
Where did a pun variant of why did the chicken cross the road appear?
answer: 1847 edition of The Knickerbocker
Potter's American Monthly
Natural Questions answer: The Knickerbocker (from the Wikipedia article "Why did the chicken cross the road?")