I have all fourteen books, but I also have two other “Oz” books that were written by other authors, The Scallywagons of Oz and Merry Go Round of Oz.
I remember (but cannot locate the reference at this time) that there were a whole truckload of other Oz books that were written by other authors. How is this possible? Is it like the “sequel” to Gone With the Wind, in which the Mitchell estate authorized Alexandra Ripley to write Scarlett? Or did copyrights not exist in the as they do today, so anyone who wanted to continue the Oz story could without fear of lawsuits?
After L. Frank Baum passed over, the publishers designated Ruth Plumly Thompson to continue the series. I believe the publishers and not the author held the rights to the characters.
I do recall that there was a great deal of rancor between Baum and W. W. Denlow, the illustrator of the first book, as to who created the characters and cold merchandise them.
John O’Neill, the illustrator of most of the rest of the series, wrote the Scallywagons book.
How does that happen, that an author doesn’t have rights to his own books? The books were published back in 1919, so I guess the law were different back then. (Like when movie stars were contracted to a studio and not free agents). When did the laws change?
Eloise Jarvis McGraw and Lauren McGraw Wagner wrote Merry Go Round of Oz (which I actually like better than Scallwagons, not as many puns). Any relation to McGraw-Hill Publishing?
There’s also A Barnstormer in Oz by Philip Jose Farmer.
Farmer has written lots of books using other people’s characters, but I’m not sure how he gets away with it legally.
Who decides? It is a general consensus thing. There has been an active body of Ozophiles since Baum was still writing, analogous to the Baker Street Irregulars although not quite as tight-assed. Notice that the forty are referred to as “official,” not canonical.
Being the petty and obsessive type myself, I agree that Baum’s books should be considered somehow more “real” than those by any other author. (Thompson was more inventive in her characters, but she tended a bit to close to the twee for my taste. YMMV.)
Some interesting background on the post-Baum Oz books can be found in the Afterword to the later editions of David R. Palmer’s award-winning first novel Emergence – his mother was in contention to succeed Ruth Plumley Thompson but lost out to someone else, so he got a lot of the inside story on the rights to Oz as a child.