“Why did the chicken cross the road?” (joke)

“Why did the chicken cross the road? To get to the other side!” This joke is cited in print in the March 1847 The Knickerbocker (New York monthly magazine). An 1872 variant is: “Why should not a chicken cross the road? It would be a fowl proceeding.”
 
   
Wikipedia: Why did the chicken cross the road?
“Why did the chicken cross the road?” is one of the oldest and most famous riddles still in use in the English language. When asked at the end of a series of other riddles, whose answers are clever, obscure, and tricky, this answer’s obviousness and straight-forwardness becomes part of the humor.
 
Origin
The exact origin of the riddle is obscure. Its first known appearance in print occurred in 1847 in The Knickerbocker, a New York monthly magazine:
 
...There are ‘quips and quillets’ which seem actual conundrums, but yet are none. Of such is this: ‘Why does a chicken cross the street?[’] Are you ‘out of town?’ Do you ‘give it up?’ Well, then: ‘Because it wants to get on the other side!’
 
The joke may already have become widespread by the 1890s, when a variant version appeared in the magazine Potter’s American Monthly:
 
Why should not a chicken cross the road?
It would be a fowl proceeding.
 
Google Books
March 1847, The Knickerbocker, pg. 283:
There are “quips and quillets” which seem actual conundrums, but yet are none. Of such is this: “Why does a chicken cross the street?” Are you “out of town?” Do you “give it up?” Well, then: “Because it wants to get on the other side!”
 
Newspapers.com
20 February 1869, Appleton (WI) Crescent, pg. 1, col. 8:
Why does a chicken cross the road?
—Because, she wants to get on the other side.
       
8 June 1872, San Francisco (CA) Bulletin, suipplement, pg. 2:
Why should not a chicken cross the road? It would be a fowl proceeding.
 
Google News Archive
31 August 1872, Sydney (Australia) Mail, pg. 283, col. 4:
Why should not a chicken cross the road? It would be a fowl proceeding.
 
Google Books
April 1880, Potter’s American Monthly, pg. 319, col. 2:
Why should not a chicken cross the road? It would be a fowl proceeding.