Dr. Seuss aka Theodor Geisel (1904-1991) almost didn't become a writer/illustrator of children's books. In 1936, he tried to sell a manuscript titled A Story No One Can Beat to publishers who rejected it for many different reasons (some didn't like the cartoon art, some didn't like the verse, some even thought it encouraged children to lie to parents, etc). Seuss was about ready to burn the manuscript and give up when by chance he encountered a classmate from Dartmouth who had just become an editor at Vanguard Press. Vanguard published the book as And To Think That I Saw It on Mulberry Street and that launched his career.
Let's say the POD is that Seuss never meets this classmate and burns the manuscript as he planned. Without Dr. Seuss and his memorable creations (the Cat in the Hat, the Grinch, the Lorax, etc), what kind of butterflies would this have on children's literature or even popular culture?