Don't forget one of the biggest of them all, Clark Gable. He joined up after his beloved wife, Carole Lombard, was killed in an airplane crash. Like Jimmy Steward, Gable joined the Army Air Corps, and he also flew combat missions.
That's a shame about Carole Lombard--she was traveling for the troops or something (USO?) when her plane crashed.
So, what was the story with John Wayne and WWII. He was no longer a kid then, but not too old. I noticed Tall in the Saddle was made during the war.
Did he have injuries from his days as a stunt man that kept him out of the war?