When I teach my Children's Literature course, I always start with a lecture on the "Golden Age" of children's literature--starting with Alice's Adventures in Wonderland and ending (to my thinking) with Peter & Wendy. I wrap up the lecture by identifying six Golden Age children's authors who set the template for what the genre would become in the century to follow. On the list is L Frank Baum, who I credit with creating something that has perhaps had the greatest impact on contemporary storytelling: platform worldbuilding.
The 1939 movie has made such a cultural impact that it's hard to remember the Oz books for what they really are. Baum's books weren't just about Dorothy and Toto. There were dozens of Oz stories containing hundreds of characters. The books continued even after his death. Baum himself wrote 18. They were published around the holidays and it was a tradition among children to get the new Oz book for Christmas. He wasn't just telling a single story, Baum was building a WORLD.
Storytelling utilizes three main tools: character, setting, and action. At various points in history, popular stories have emphasized one or another of these elements. Presently, we are entering an age that celebrates setting above all. Today we value not just compelling narratives (Shakespeare) or characters (Dickens), but settings rich enough to contain a multitude of characters and plots. Think of visionaries like Tolkien, Gygax, Lucas, Roddenberry, Jack Kirby -- their legacies are not single narratives so much as entire universes. Part of the reason this brand of storytelling has ascended is because it allows the creation of franchises--which are very valuable. Another bigger reason is because it fits more seamlessly into interactive storytelling (video games); what is World of Warcraft if not an ever-expanding narrative landscape?
One might argue that Scott or Homer worked within this tradition, but I think the real innovator was Baum. In Oz, Baum created a place that could contain infinite stories ... which was a pretty radical concept at the time. So the next time you see yet another Star Wars movie in the cineplex, or yet another version of Zelda at Gamestop, thank Baum. or curse him.