Find the Variables (Movie Connect: Great Depression)

Name the movies 'A' and 'B'(and also, try to find out 'C' and 'D').

Both the movies 'A' and 'B' were set during the 'Great Depression' times(real-stories).
The protagonists of 'A' and 'B' had to struggle a lot during the Depression days, but with typical Hollywood-grit they fight back and show the rest the 'art of fighting spirit' and everyone can leave the theatres feeling-good.

Clues:
-> The character(playing the title-role) in 'B' lived for just 14 years.
-> The movie 'A' had actor 'C', who got nominated for Best-Supporting Oscar for his role in 'A'.
-> 'C' is currently playing the lead role in the movie 'D'.
-> The director of 'D' had earlier famously told:
"I'm going to stop making movies if they end the cinema experience. If there's a last film that's released only theatrically, it'll have my name on it. This is life or death to me. If you tell audiences there's no difference between a theatrical experience and a DVD, then that's it, game's over, and that whole art form is going to go away slowly. Movies will end up being this esoteric art form, where only singular people will put films out in a small group of theaters."

Surprisingly, both of these movies 'A' and 'B' did not make much of an impact in Oscars.

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