With The Wonderful Wizard of Oz (1900), L. Frank Baum created a new kind of plain-language fairy tale, purely American, modern, industrial, and for the most part non-violent. He said in his introduction that the book "was written solely to please children of today. It aspires to being a modernized fairy tale, in which the wonderment and joy are retained and the heart-aches and nightmares are left out." The Wizard of Oz —"Wonderful" was dropped in later printings—became an institution for generations of children. Reinforced by the 1939 MGM film, the story and its messages quickly became a part of American culture. The belief that the power to fulfill your deepest desires lie within yourself, that good friends can help you get where you are going, and that not all Wizards are for real has offered many comfort through turbulent times.

The hero...