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..
Father Goose: His Book
Father Goose: His Book is a collection of nonsense poetry for children, written by L. Frank Baum and illustrated by W. W. Denslow, and first published in 1899. Though generally neglected a century later, the book was a groundbreaking sensation in its own era; "once America's best-selling children's book and L. Frank Baum's first success," "Father Goose" laid a foundation for the writing career that soon led to "The Wonderful Wizard of Oz" and all of Baum's later work.