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..
The Magical Mimics in Oz
The first edition of "Magical Mimics" was not a commercial success; a backlog of unsold copies delayed the next Oz book, originally projected for 1947, until 1949. Kramer's illustrations for "Magical Mimics" have been criticized as deficient. "Magical Mimics" had been out of print for decades when the International Wizard of Oz Club issued a reprint in 1990, with a useful Afterword by Michael Gessel. Other editions followed, from Books of Wonder (1991) and Kessinger (2007).