'The book, 'Wonderful Wizard of Oz,' was a political allegory for American politics at the dawn of the 20th century. Dorothy represents the nobility and innocence of middle America. The Tin Man is industry. The Scarecrow is agriculture. Mr. Baum depicted the bimetallism argument of the late 19th century between Eastern capitalist lenders and Midwestern farmer-borrowers, a colorful metaphor. The city Dorothy and friends seek is emerald green like money; the fraudulent Oz hides behind green shades; the fed. The yellow brick and Dorothy's silver slippers represent the argument over whether the United States should have a gold and silver or gold only currency standard. The ruby slippers worn in the film version are indeed a departure from the original book.'