In 1900, a china salesman turned author hit paydirt when his manuscript that he referred to as a "modernized fairy tale" was published. Almost 110 years later, The Wizard of Oz continues to delight children of all ages. The book is important in the world of series book collecting. The book spawned a whole series of Oz books, creating a significant niche for publishers, the childrens book.
40 Oz books comprise the series. After Baum's death in 1919, the publishers, Reilly and Lee, hired a young woman to continue the series. A new Oz book was published yearly until 1939, when Ruth Plumly Thompson left her post as "The Royal Historian of Oz". The author's illustrator, John R. Neill, continued the series as author until his death. Jack Snow, Rachel Cosgrove, and Eloise Jarvis McGraw and Lauren McGraw Wagner contributed their own entries in the canon before Reilly and Lee pulled the final plug in 1963 with Merry Go Round in Oz.
Check out Ebay at any time, and a plethora of Oz books in various formats are available for a new collector. But buyer beware... Oz books are sometimes very overpriced, and a novice should make sure he or she knows something about the books before buying a rare Oz book that is really not worth its starting bid.
All Oz books originally published before 1935 had color plates in its pages. In 1935, publisher Reilly and Lee discontinued the plates. Books may have a copyright page of 1907, but if there are no color plates, rest assured it is NOT a first printing of the book. These books are not worth nearly the same as a book that has its color plates. I personally would not spend much more than $50.00 at this time for a pre-1935 book with no color plates.
In comparison, a good solid copy of an Oz book complete with its plates is worth $200-300.00. Older books in the series are worth more, especially the early titles that have Baum as its author. Reilly and Lee was first known as Reilly and Britton, and if this name appears on a spine, you have an older title from 1918 or before.
Two places I would suggest to the novice to learn more about the Oz books. Get a copy of The Book Collectors Guide to L. Frank Baum and Oz by Paul R. Bienvenue. This lavishly illustrated volume was published this Spring, and is invaluable when detailing the various printings of the entire Oz canon. I also suggest you check out Fred Trust's web site www.rareozbooks.com. Fred has a wonderful array of Oz books for sale, and is a walking encyclopedia to worth and availability of these classic books.
Nancy Drew, The Hardy Boys, and all that were to follow owe much to the Oz books. Publishers developed the children's book genre around these books. It was the tradition of a new Oz book each Christmas that helped develop other series in the years to come!