Can you name the first movies in which each of these actors appeared?

@TexChik Those are all good guesses. I did not realize Duvall was in True Grit which I watched as a kid. The answers -- see clips for two below.
Duvall: To Kill a Mockingbird (Boo Radley)
Dreyfus: The Graduate
Depp: A Nightmare on Elm Street.

@PowerofStories Duval was Ned Pepper. Wow now that you mention it wasn't it his mother that did Hoffman? Depp 🙄

@TexChik If I'm understanding your question correctly, Anne Bancroft played the mother of Kathrine Ross in the Graduate and her character, Mrs. Robinson was the one who seduced Dustin Hoffman.

I saw True Grit as part of a double feature during my first trip to a Drive In movie when I was a kid. I don't remember how old I was, but the whole experience was a thrill.