With a PoD no earlier than October 13, 1938 (the day shooting commenced) how does production on The Wizard of Oz get derailed so that an adaptation of the book is not released prior to 1945?
As the others have pointed out, the 1939 musical was not the first or only adaptation of the book. Baum himself directed a few silent versions. What the 1939 production did was
prevent any future adaptations apart from low budget, narrowly distributed "re-imagined" versions or parodies.
As for delaying or preventing the 1939 version, actual cast and crew deaths would be a good start. The original Tin Man, Buddy Ebsen, nearly died thanks to inhaling the powdered aluminum in his make-up for only a few days and Wicked Witch Margaret Hamilton was badly burned when some SFX reacted with her copper-based make-up. Kill off a few people on the set and production will be shut down.
Considering how tightly scheduled stages, actors, crafts, writers, directors, and the like were under the studio system, delay the production long enough and everyone is going to be off doing something else very quickly and therefore next to impossible to reassemble.
Also, the name escape me, but didn't the fellow who finally finished direction of
Gone With The Wind spend a few weeks filling in as a director on the
Oz before moving on to
GWTW? If memory serves, he made some substantial and in retrospect important changes too, among them removing the blond wig Garland had been wearing.
Prevent his appearance as a pinch hitter and the studio might be so disappointed in the rushes that the film is never released.
When would the first adaptation then come out?
The early 1950s when Hollywood was looking for any gimmick to "fight" television. We'd see a mega budget, cinemascope, technicolor, Cecil B. Demented extravaganza with oodles of star power, stunt casting, and every other trick up the studio's sleeve. Think Dorothy & Co. given the
Ben Hur/Ten Commandments treatment and you won't be too far off the mark.
Like the others, I'd bet the later version won't be a musical.
And what would be the effects (culturally, cinematically, and otherwise) of this change?
Profound and widespread, as EN1 correctly pointed out. References to the film's dialog, scenes, characters, all of it are embedded in our culture down to the level of our language.
