So, with Legends of Oz: Dorothy's Return out, it's joining a huge lineup of Oz films. Let's take a look down memory lane at the previous Oz film sequels.
Quite seemingly, the first film that served as a sequel to The Wizard of Oz is now lost. The Selig Polyscope Company produced a number of short films to accompany the short Wonderful Wizard of Oz film in 1910. Sadly, only the first one has turned up. While miraculous film finds are made all the time, my hopes are low for finding further Selig Oz films. The extant Selig film was turned up in the 1980s, and it is now 2014 and no further discoveries have been reported. Or perhaps Selig's other Oz films are so oddball that they've yet to be identified. (As The Fairylogue and Radio Plays was one presentation and not individual films, I'm not counting those here.)
Do the 1914 Oz Film Manufacturing Company films count as Oz sequels? I'd say no. They were not marketed as sequels, and it seems that each film was meant to stand as an independent piece. There is little to no continuity between the films.
Thus, the first extant Oz sequel film is the 1932 The Land of Oz by the Meglin Kiddies. The little short is very loosely based on the Baum book with the Scarecrow running the Emerald City, which Jinjur takes over with the help of Mombi who has a boy named Tip as a slave. Dorothy is also in the plot, bringing a statue of the Tin Woodman to life with the Powder of Life and later getting kidnapped and daring to escape from Mombi. It would seem to be considered a standalone piece, but the film's title says that it is a sequel to The Wizard of Oz. Sadly, there is no easy way to see the film as it has never been released on home video. Apparently, a film archive can arrange a screening. Willard Carroll rediscovered the film and it seems that it was screened at the Centennial Convention. A DVD transfer was screened at the 2012 Winkie Convention. The second half of the film's audio is missing.
So, what was the next Oz sequel? We flash forward 25 years to find Walt Disney with his abandoned Rainbow Road to Oz. We've discussed that plenty of times, so I'll link to my specific entry about that.
In 1961, Shirley Temple offered her own take on The Marvelous Land of Oz with her television show, but although it was based on the second Oz book, the production actually seems to be designed to be a standalone piece. Thus, Shirley Temple, you get a pass in our lineup of Oz sequels.
Three more years would bring us the first bit of animated Oz that was not a short: Videocraft's Return to Oz. It was a duo-sequel, following up the Tales of the Wizard of Oz cartoon series and also offering a sequel to the Wizard of Oz story. It took full advantage of the public domain status of The Wonderful Wizard of Oz by reworking the plot into a sequel: the Wicked Witch is back and has robbed Dorothy's friends of their gifts from the Wizard. Another Kansas twister whips Dorothy and Toto back to Munchkinland, where she rejoins her old friends to find the Wizard again while keeping one step ahead of the Wicked Witch, who's got a few new tricks up her sleeve. (Voicing Dorothy was Susan Conway, while singing her songs was another Susan: Susan Morse, who happens to be a friend!)
Another musical sequel would follow in 1969: the kiddie matinee The Wonderful Land of Oz, based on The Marvelous Land of Oz. Live action, and with so many thrills, you'll be Ozified! Or ossified. The plot actually stays very close to Baum's original book with a few cuts. The quality of the production is pretty low, and the acting seems rather amateurish, aside from Channy Mahon who plays Tip, who really just should not have been cast as the lead character in a movie.
Finally getting released in 1972 was Journey Back to Oz by Filmation. The voices had been recorded ten years earlier and the animation begun, but when funding ran out, the project was in limbo until it was finally completed. It's generally given a good claim to being the official sequel to the MGM Wizard of Oz due to a cast member appearing in the film: Margaret Hamilton as Aunt Em. Liza Minnelli, Judy Garland's daughter, took her mother's role of Dorothy and made it her own for the film, though her voice is reminiscent of Judy's at many points.
The plot? Dorothy returns to Oz via cyclone and with help from Pumpkinhead (Paul Lynde) and Woodenhead (Herschel Bernardi), races to the Emerald City to warn the Scarecrow (Mickey Rooney) of the wicked witch Mombi (Ethel Merman) invading with her magic green elephants!
With home video and more Oz books going into the public domain in the 1980s, more Oz sequels popped up: Dorothy in the Land of Oz (the Oz cartoon of many names, including Dorothy and the Green Gobbler of Oz) featured Dorothy returning to Oz via the Wizard's turkey balloon and joining Jack Pumpkinhead, the Hungry Tiger and Tik-Tok to defeat Tyrone the Terrible Toy Tinkerer. The Children's Theater Company of Minneapolis filmed their stage version of The Marvelous Land of Oz and released it to home video, but although it references the first Oz story, it is again a separate piece. 1987 brought the direct-to-video Dorothy Meets Ozma of Oz, an adaptation of Ozma of Oz, set up to be a sequel to Wizard, though no particular version.
And of course, Disney released Return to Oz in 1985. but I've written about that here.
The Marvelous Land of Oz was adapted as part of the PanMedia/Cinar anime series, but as that series adapted several Oz books as one long storyline, it is a little less of a sequel. It follows the book's plot admirably despite adding Dorothy, but begins to take many twists, including Glinda transforming herself, which actually goes against what she says in the book.
The 1990s did not offer many Oz productions, but we did get DiC's Wizard of Oz series based on the MGM film in which Dorothy returns to Oz with faulty Ruby Slippers, a resurrected Wicked Witch, and the Wizard at the mercy of a cruel wind. Dorothy's friends have had their gifts stolen, so it's up to them to try to bring peace to Oz once again.
The 2000s finally brought more Oz spin-offs, but really no sequels until Legends of Oz: Dorothy's Return.