“What’s the tallest building?” or “What building has the most stories?” (joke)

There’s an old riddle about the tallest building:
 
Q: What’s the tallest building?
A: A library because it has so many stories.
 
The joke has been cited in print since at least 1929.
       
 
22 December 1929, Chicago (IL) Daily Tribune, “The Chuckle Corner,” pg. N2, col. 6:
Teacher—What building has the most stories?
Student—A library.
MARIE KONWENT.
5223 West 30th place.
 
2 June 1940, Illinois State Journal (Springfield, IL), “The Chuckle Corner,” pg. 10, col. 7:
Riddle: What building has the most sotires?
Answer: A public library.
—James Roberts.
 
12 January 1941, Boston (MA) Herald, “Good Riddles, Jean!,” pg. 12B, col. 4:
Q.—What building in New York has the most stories?
A.—The Library.
(...)
JEAN KAPLAN.
   
26 April 1956, The Independent (Long Beach, CA), “Bert Kelley Says,” pg. 24, col. 1:
“What’s the tallest building in the world?” Egghead will ask. Having baffled the party, Greb proudly announces: “The library—because it’s got more stories.”
 
Google News Archive
11 August 1994, The Blade (Toledo, OH), “Laugh now, for tomorrow we must study” (Times-Post News Service), pg. 42, col. 1:
TEACHER: What’s the tallest building in the world?
JOANNE: The Library of Congress.
TEACHER: Why the Library of Congress?
JOANNE: Because it has the most stories.
 
Google Books
81 Fresh & Fun Critical-thinking Activities:
Engaging Activities and Reproducibles to Develop Kids’ Higher-Level Thinking Skills
By Laurie Rozakis
New York, NY: Scholastic Professional Books
1998
Pg. 98:
What’s the tallest building in your city?
The library — it has the most stories.
 
Google Books
Laugh and Learn Grammar
By Debra J. Housel
Westminster, CA: Teacher Created Resources
2007
Pg. 10:
What’s the tallest building in any city?
The library, because it has the most stories.
 
Google Books
Horrid Henry’s Jumbo Joke Book (3-in-1)
By Francesca Simon
London: Orion’s Children’s Books
2015
Pg. ?:
What’s the tallest building?
A library because it has so many stories.
 
Twitter
Puns of Jokes
‏@punsofjokes
What’s the tallest building in the city? ...The library cause it has so many stories.  #pun #funnystuff
7:12 PM - 2 Jul 2015