Lots of writers loved the Oz books, and no exception was Eloise Jarvis McGraw. She and her children read the Oz books together, and by the 1960s, she was an established author with such books as Moccasin Trail, Mara, Daughter of the Nile, and The Golden Goblet under her belt. These books proved popular with readers, librarians and publishers.
From what I gather, while reading a John R. Neill book (who wants to bet it was Scalawagons?), Eloise felt she could write a better Oz story, and she began writing one, with her daughter Lauren McGraw Wagner (at least it was then!) helping come up with story ideas and helping her edit and organize her ideas so well, Lauren was given co-author credit when the book was submitted to Reilly & Lee.
Merry Go Round in Oz was released in 1963 as the fortieth Oz book published by Reilly & Lee (they had since published their own edition of The Wizard of Oz). Dick Martin came in as illustrator, having done a lot of original Oz artwork for the International Wizard of Oz Club, so really, no one else was seemingly as suited to the task.
Merry Go Round was uniform with a reprint series of Baum's Oz books that are called "the white editions" by Oz fans, due to the white spines and cover borders. The Oz books of Thompson, Neill, Snow, and Cosgrove were not released in these editions. Given the wide availability of the white editions, it would appear they sold well, but the sales of Merry Go Round were not impressive and likely sent the message that Baum's original 14 novels were the best loved Oz books, and so the other 26 Oz books were not reprinted and began to become difficult to find. In fact, a first edition of Merry Go Round is actually the rarest first edition Famous Forty book, despite being the newest. (I was outbid on one just last Saturday at an auction.)
The story finds young Robin Brown (any relation to Thompson's Peter Brown?) going to a carnival with his large foster family, who often neglect and ignore him. He heads straight for the merry go round, where the ticketmaster encourages him to pull a ring and get a "free ride!" A free ride indeed, because when he does so, the merry go round horse, Robin and the ring tear off of the merry go round and fly off to Oz!
Already, I'm seeing the influence of Thompson on this plot.
In Oz, Peter finds the horse has come to life (because it's Oz) and he names her Merry Go Round. Hearing from some of the local wildlife that they are in Oz, they decide to head for the Emerald City, but not before they are caught by a bunch of fox hunters in a country called View Halloo.
Wait... Isn't fox hunting just a bit too British for an American fairy tale?
Meanwhile, in another (but not too far off) part of Oz, the tiny kingdom of Halidom discovers the final of the three circlets is now missing. The first circlet, which the king would wear on his head, gave the people wisdom. It rolled into a rabbit hole. The third circlet, which was worn like a ring, gave the people skill in crafting things. A bird flew off with it. The second circlet, which has mysteriously vanished, gave the people strength, and without it, no one feels like doing anything. Prince Gules decides to head out on a quest to recover the three circlets, and with him is his squire Fess, the Flittermouse (a winged mouse, not a bat), Fred the steed (his cousin was a Destrier!), and the fairy Unicorn.
Robin and Merry quickly get quite enough of View Halloo and depart by Merry jumping over the fence. Then they head toward the Emerald City, meeting a very Ozzy ferryman who tells them more about Ozma and that she can send Robin home and make Merry into a real horse.
Gules and Fess head through Sign Here, which is a place full of signs. But they find an oracle giving them cryptic messages about how to find the circlets. The first is disguised, the second will be found by the humblest of the party, and the third is in the hand of a "future king" and will be found in a roundabout way.
More European type fairy tale, this time even more extreme than Thompson, as well as the prophecies that were sometimes in her stories. (The Purple Prince of Oz springs to mind.) I suspect the McGraws of being Thompson fans... Now, where are our old Oz friends?
Well, we find them in chapter ten! Dorothy suggests they have an Easter party, and Ozma agrees. An egg hunt will be the main event, so Dorothy and the Cowardly Lion go to the Easter Bunny (who lives in the Munchkin Country) to get some eggs. While the Easter Bunny is busy, he manages to supply Dorothy with enough eggs for the party, and also gives her a gift for Ozma: a sugar egg with a gold band around it that shows his cavern when you look inside.
However, Dorothy and the Lion have trouble finding their way out and instead run into Prince Gules and his party. They decide to join forces.
Robin and Merry find themselves in Roundabout (a round city full of round people), where Roundelay, the sphere-seer, announces Robin as the new king due to a prophecy. (Yes, another one.)
Dorothy is made a prisoner of the Land of Good Children, but thanks to some surprising quick thinking by Prince Gules, they rescue her and escape, discovering the first circlet is the gold band around the sugar egg for Ozma. Dorothy lets them have it, of course, deciding that it can easily be replaced, and Ozma would understand the circumstances.
Gules' company find Roundabout and meet Robin, Merry, and Roundelay, who is recognized as a peddler who had been seen in Halidom. Sure enough, the people talk about "the shining symbol" of Roundabout, which Gules realizes must be one of the circlets. Roundelay has put at the top of a winding staircase, protected by a machine that would make retrieval impossible for anyone climbing it. But the Flittermouse proves "the humblest" by flying up and getting it himself. The extra strength allows them to escape Roundabout and return to Halidom in the valley of Pax-on-Argent.
It is discovered that Sir Greves worked with Roundelay to steal the second circlet, and for that crime, he must be banished. The third circlet, it is discovered, was the ring that Robin pulled that brought him to Oz. It just looked brass.
Ozma arrives on the scene, congratulating Gules on completing his quest, and since Sir Greves is sorry for his action, he is made king of Roundabout, since he's a round fellow himself. (He helped steal the circlet in return for a delicious recipe that will help Roundabout.) And rather than be sent home, Robin is allowed to stay in Oz, while Merry is now content to be a live merry go round horse rather than a real one.
As I said, a lot of the McGraws' new touches to Oz feel European and British and a little out of place for an Oz story. A lot of the story is reminiscent of Thompson's stories. Merry's desire to be a real horse eventually turning into contentment with her current state brings to mind Benny in The Giant Horse of Oz. The plot itself reminds us a little of The Hungry Tiger of Oz, though the plot feels tighter than that book. (Eloise mentioned that she got an angry letter from an Oz fan practically accusing her of plagiarism from that book and Rinkitink in Oz. She commented that while she did see the similarity with Hungry Tiger, it was not intentional and that with a long-running series, it was bound to happen.)
All together, Merry Go Round in Oz is a very fun book that is easy to like, but it doesn't feel extremely Ozzy with all the European influence. Yes, Thompson was guilty of such as well, and even Baum had some traditional style kingdoms in his stories. But here, there is not enough Ozzy wit and magic in Halidom and the neighboring kingdom of Troth to make it work, unlike in Thompson and Baum. (As it turns out, Lauren was an Anglophile at the time and couldn't resist adding these touches to her favorite fairyland.)
Merry Go Round in Oz was the last new Oz book published by Reilly & Lee, who were, at the time, now part of the Henry Regnery Company. Soon, the Reilly & Lee line was restricted to Oz books and they relinquished their rights to be the only ones publishing new Oz books, allowing other literary works to come about.
Reilly & Lee is still around, in a sense, though they don't publish Oz books anymore or go by that name. In the 1980s, they had become Contemporary Books, and are now part of McGraw-Hill. (As a personal aside, when I was studying for my GED, I was pleasantly surprised to see one of the books I was studying from was published by Contemporary Books. That tells you how much they've changed.)
So, that is the story of how what fans now call "The Famous Forty," "The Official Oz Books," or "The Canon" came to be.
But since you've been following along with these blogs, you know that the author's last Famous Forty book was never their last Oz work. Merry Go Round in Oz, while being the last Famous Forty book, was the only such book to be published after the International Wizard of Oz Club was founded. There was now a dedicated fan base who thoroughly enjoyed this new Oz story and sent the new authors many letters thanking them for it. They were even invited to conventions, and seeing the love for Oz and their own work, you may very well guess that Eloise and Lauren soon felt the urge to write another Oz story!