Nearly 4 full years after adapting Dr. Seuss' How The Grinch Stole Christmas, Chuck Jones worked his magic on a Seuss property he was remotely familiar with.
Horton Hears a Who was the 2nd and last Seuss adaptation to be produced by MGM for CBS. The following year, DePatie-Freleng took over the license with The Cat in the Hat. Hans Conried (ex-Hoppity Hooper), who top-lined a live-action Seuss adaptation, "The 5,000 Fingers of Dr. T.", a few years earlier, narrates and voices Horton in much the same manner that Boris Karloff handled the Grinch. Jones, June Foray, and Thurl Ravenscroft (uncredited) are among the other voices heard.
Horton had previously been on the big screen, adapted by Warner Bros. for an animated short some years prior. In 2008, the story was retold as a feature length movie, with Steve Carell & Jim Carrey lending their voices. Unfortunately, the need to stretch out the original tale neutered the plot and watered down the story.