The Oz books form a book series that begins with The Wonderful Wizard of Oz (1900) and relate the fictional history of the Land of Oz. Oz was created by author L. Frank Baum, who went on to write fourteen full-length Oz books. All of Baum written books are in the public domain in the United States. Even while he was alive, Baum was styled as "the Royal Historian of Oz" to emphasize the concept that Oz is an actual place. The illusion created was that characters such as Dorothy and Princess Ozma related their adventures in Oz to Baum themselves, by means of wireless telegraph.
Baum also wrote Oz-related stage plays: The Wonderful Wizard of Oz (1901) with music by Paul Tietjens and Nathaniel D. Mann, The Wizard of Oz (1902) (music by Tietjens et al.; with jokes by Glen MacDonough), The Woggle-Bug (1905) with music by Frederick Chapin, The Rainbow's Daughter, or The Magnet of Love (February 1909) with music by Manuel Klein, revised in April 1909 as Ozma of Oz, and ultimately produced, with music by Louis F. Gottschalk as The Tik-Tok Man of Oz. Also in 1909, he wrote a play called The Girl from Oz. The manuscript is held in the archives at Syracuse University, but apparently its relation to Oz is little more than nominal (it is also known as The Girl from Tomorrow and was later adapted for radio by Frank Joslyn Baum), as is also the case with the short story, "The Littlest Giant", a rather brutal tale designated in two lines to be in the Gillikin country of Oz. With Gottschalk writing the music, he wrote an unproduced stage version of The Patchwork Girl of Oz in November 1913, that was developed into the film scenario.