The Wonderful Wizard of Oz, the book’s original title, was written by L. Frank Baum, published in 1900. The first play adaptation was two years later. It was a musical version where the word “Wonderful” was dropped. That shortened title remained from then on. The success of his book —it sold over three million copes until it became in the public doman in 1956—encouraged Baum to write thirteen more "Oz" books.