Copyright status of The Wizard of Oz and related works in the United States
"The Wonderful Wizard of Oz" was published in 1900, and was the first to enter the public domain in "1956". This allowed Reilly & Lee, the publisher of all the other Oz books (as well as Baum's other books) to issue their own edition of "The Wizard of Oz", which had previously been published by George M. Hill Company and later by the Bobbs Merill Company after Hill went bankrupt..
Political interpretations of The Wonderful Wizard of Oz
Political interpretations of "The Wonderful Wizard of Oz" include treatments of the modern fairy tale (written by L. Frank Baum and first published in 1900) as an allegory or metaphor for the political, economic, and social events of America in the 1890s. Scholars have examined four quite different versions of Oz: the novel of 1900, the Broadway play of 1901, the Hollywood film of 1939, and the numerous follow-up Oz novels written after 1900 by Baum and others.