Nevertheless, Mother Goose did receive critical acclaim, opening doors for future works. Still, Baum had to earn a living, and in 1898 he began publishing The Show Window, a magazine for those who prepared window displays. Meanwhile, he personally published a small book of poetry for family and friends in 1898, By The Candelabra's Glare (99 copies). One artist who contributed drawings for the project was W.W. Denslow, who would soon collaborate with Baum on his hugely successful early books. The two would begin collaborating on a book featuring Baum's rhymes and Denslow's illustrations, Father Goose; His Book. It was a surprise success, eventually selling over 100,000 copies. Now, after years of struggling, Baum was achieving dual successes, writing children's books and about store window displays. The result was that Baum needed to become very prolific as a writer. In 1900, he wrote several children's books, including his Army Alphabet, Navy Alphabet, and A New Wonderland; he wrote The Art of Decorating Show Windows and Displaying Merchandise (don't read this one to your children at bedtime), and ... oh, yes ... he put out a book with Denslow entitled The Wonderful Wizard of Oz. You know the rest.

The Wizard is one of the most acclaimed and popular of children's books ever written. The 1939 film version, starring Judy Garland, is on everyone's list of the best movies ever made. Baum's career and success was sealed with the publication of this book. Fortunately, he remained a prolific writer through the remainder of his life, which concluded in 1919. His next several children's books would take him away from Oz, but the fantastic success of the Wizard would return him to the theme in 1904. He then published the second of what would be 14 Oz books he would write. It all makes for many opportunities to collect his numerous Oz books in so many different iterations. Nevertheless, he would continue to write non-Oz titles as well. Additionally, Baum would disguise his identity to write different stories, his works being published under the pseudonyms Floyd Akers, Laura Bancroft, John Estes Cooke, Capt. Hugh Fitzgerald, Suzanne Metcalf, Schuyler Staunton, Edith Van Dyne, and anonymously. Collecting Baum offers practically unlimited opportunities.

Nor did Oz die with Baum. Collecting Oz affords opportunities well beyond Baum's work. It was such a successful series that the publisher continued the stories after Baum died. The franchise was next turned over to Ruth Plumly Thompson, who wrote more Oz books than did Baum. She wrote 19 between 1921 and 1939. Next, the title of "Royal Historian of Oz," and writer of the books was passed on to John R. Neill. Neill had illustrated many of Baum's works, as far back as the second Oz book in 1904. He would continue with three Oz books, after which writing was turned over to Jack Snow, then Rachel Cosgrove Payes, and finally Eloise Jarvis McGraw. Even this does not cover all the material available to Oz and Baum collectors. There were many Oz-related books not within the series. Baum wrote some short stories using Oz characters, works were published about the film version, and so on. Later writers also contributed "extra-canonical" Oz books. These are works not officially considered to be part of the series, but about Oz anyway. For example, Neill had an uncompleted manuscript in progress when he died, which was completed and published over 40 years later in 1995. Bienvenue lists the last canonical Oz book as McGraw's Merry Go Round in Oz, published in 1963, but she issued a title as late as 2001. And, various items Baum wrote continue to show up occasionally, and there may well be more things he created yet to be published, even over a century later.