What is the conflict of the story in The Wonderful Wizard of Oz?

A main conflict in The Wonderful Wizard of Oz is Dorothy's desire to get back home to Kansas. A tornado has dropped her, her dog Toto, and her house, in Oz, to her a very strange land. The house has also literally fallen right on top of the Wicked Witch of the East, killing her. This spreads joy through Oz, but also creates another obstacle for Dorothy in getting home. The Wicked Witch of the West, who is the dead witch's sister, is very upset that Dorothy killed her sibling. She captures and enslaves Dorothy, forcing her to work as servant.
Another conflict is between perception and reality. Dorothy and her new Oz friends are all on a quest for something they feel they lack. They don't realize, however, that they already possess the resources they need. Dorothy, for instance, only finds out at the end of the book from Glinda that all she has to do is tap together the heels of her silver slippers three times and make a wish to get back home.