A wonderful fantasy, but very few people know about the political allegory intended by L. Frank Baum, who wrote the book in the era of Populism and the 1890s. The story is the quest for Free Silver, with Dorothy representing Kansas (the root of the Populist movement); the scarecrow the BRAINLESS agricultural midwest; the tin woodman the HEARTLESS industrial north; the cowardly lion was William Jennings Bryan. The witches represent the different regions, and their competition either helpful to the cause (north vs south, post Civil War) or destructive (west vs. east). The Yellow Brick Road (gold) leads to the Emerald City which was of course Free Silver. A thousand apologies for not saying what the Winged Monkeys represent, but you should be able to guess. This was the 1890s after all, and not very PC.