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..
Copyright status of The Wizard of Oz and related works in the United States
The 1939 version of "The Wizard of Oz" is the most well-known adaptation of "The Wizard of Oz"; in many respects, its popularity surpassed the original book. Its copyright was renewed in 1967, so it will remain copyrighted for a 95-year term, entering the public domain in 2035. This has caused issues for most subsequent Oz adaptations, especially because WB (the current owners of the copyright), have been very aggressive in protecting the film's copyright. Recently, they went after potential merchandise for the upcoming "".