“What’s the difference between one yard and two yards?”/“A fence.”

“Yard” can mean a unit of length equal to three feet, and it can also mean the property surrounding one’s house. A riddle is:
   
Q: What’s the difference between one yard and two yards?
A: A fence.

 
The joke has been cited in print since at least 1878.
 
           
Newspapers.com
22 February 1878, The Star of Pascagoula (Pascagoula, MS), “Funnygraphs,” pg. 4, col. 3:
Teacher—“What is the difference between one yard and two yards?” “A fence,” replied Tommy Blazes, and then Tommy sat down fourteen times on a ruler.
 
Newspapers.com
7 March 1878, Murfreesboro (NC) Enquirer, pg. 3, col. 2:
‘What is the difference between one yard and two yards?’ asked the teacher in arithmetic. ‘A fence,’ said Tommy Beals. Then Tommy sat down on the ruler fourteen times.
 
Google Books   
February 1880, St. Nicholas magazine, pg. 359:
RIDDLE.
What is the difference between one yard and two yards?
   
Google Books
Conundrums, Riddles and Puzzles:
Containing One Thousand of the Latest and best Conundrums gathered from every conceivable source

By Dean Rivers
Philadelphia, PA; The Penn Publishing Company
1910
Pg. 54:
What is the difference between one yard and two yards? A fence.
     
Google Books
The Stay-at-Home Book for Boys and Girls
By Robert Cleveland
New York, NY: Greenberg
1944
Pg. 88:
What is the difference between one yard and two yards? A fence.
 
Google Books
Complete Speaker’s and Toastmaster’s Library
By Jacob M. Braude
Englewood Cliffs, NJ: Prentice-Hall
1965
Pg. 29:
Fence: the difference between one yard and two yards.
 
Google Groups: balt.forsale
Free homepages . . . ..
Ragga
Aug 19, 1996, 3:00:00 AM
(...)
... Fence: The difference between one yard and two yards. . . . . . . .—- Blue Wave/QWK v2.10
     
Google Groups: alt.brain.teasers
Playing with Conundrums
Carl G.
Jan 21, 2000, 3:00:00 AM
(...)
5. What is the difference between one yard and two yards?
Usually a fence.
     
Google Groups: alt.humor.puns
“Puns of the Weak” 7/14/00
Stan Kegel
Jul 15, 2000, 3:00:00 AM
(...)
What is the difference between one yard and two yards? A fence (Syman Hirsch)
   
Twitter
Paul
@forces2
What’s the difference between one yard and two yards? A fence
2:45 AM · Jun 21, 2009·Twitter Web Client
 
Twitter
Annoying Orange
@annoyingorange
HEY! What’s the difference between one yard and two yards? A fence! HAHAHA!
2:04 PM · Feb 9, 2012·TweetDeck
   
Google Books
Conundrums, Riddles and Puzzles
By Dean Rivers
Good Press
2021
Pg. ?:
What is the difference between one yard and two yards? A fence.
 
Reddit—Cleanjokes
Posted by u/SheldonE65 October 21, 2021
What is the difference between one yard and two yards?
A fence
COMMENTS
thissucksassagain
one yard