Apparently, the Mitchell family was not particularly pleased with this film. Some of it was because the star, Gary Cooper, was nothing like Mitchell...neither in temperament nor size. Still, it is a reasonably good movie...one worth seeing.
The story is about Billy Mitchell, an Army officer who deliberately sacrificed his own career because he strongly felt the military was unfairly discounting air warfare. For example, in some tests, his superiors deliberately rigged the procedings to make the airplanes seem ineffective against naval ships. So, to prove his point, he ordered his men to make a more realistic attack...which resulted in his demotion. Still, he pressed until ultimately he was court martialed for insubbordination. This film is about the events leading up to this trial and a major portion of the film is a recreation of the trial.
Considering I am a retired history teacher, I am thrilled that this forgotten period in history hasn't been completely ignored. While a few things here and there were altered for cinematic reasons, it generally sticks to the facts...something unusual for Hollywood. Overall, it's also pretty compelling and worth your time.