From Neil Gabler's book on Walt Disney, about the man's work at the 1964 New York World's Fair:

The basic idea of the attraction, appropriate to UNICEF, was a large boat that would float on a canal through a universe of small animated dolls representing all the countries of the world and demonstrating the fundamental unity of mankind—a platitude given the archetypal Disney treatment. Originally Walt had thought to have the dolls “sing” their national anthems, but the result was cacophony. Instead he asked the Sherman brothers, who had written songs for various films at the studio, to write a composition that could be sung by all the children. Harriet Burns, who worked on the exhibit, remembered Walt telling the Shermans offhandedly, “It's a small world after all,” which became the title of their song and of the attraction.

I was like: “Oh, so that was Walt Disney.” That song. It's something that I kept thinking throughout the book. Oh, so we might not know “Three Little Pigs” if it wasn't for Disney. We wouldn't have “Who's Afraid of the Big Bad Wolf.” The Davy Crockett coonskin cap craze in the ‘50s. EPCOT. All Disney.

I’ve never been to Disneyland or Disneyworld, but I still should‘ve known about “Small World,” since it was so expertly parodied by “The Simpsons” when they went to Duff World and Lisa has that LSD-like experience during the knockoff “Small World” boat ride. 

Duff World ... Hoo-rah!

Other great takes of latter Disney include the last chapter in E.L. Doctorow’s “The Book of Daniel” (for Disneyland) and the last part of George W.S. Trow's epic essay “Within the Context of No Context” (for ‘64 World’s Fair). Both are required reading.