'Forrest Gump' at 25: Film's screenwriter on the deleted MLK scene, never-used special effects and a Billy Crystal speech that didn't make the cut

Forrest Gump, the iconic comedic drama that took viewers on a sprawling tour of three decades worth of American touchstones through the eyes of its titular hero (Tom Hanks), turns 25 this weekend. Following its July 6, 1994 release, the film turned into a cultural touchstone of its own, reigning over the year’s box-office charts with a whopping $329 million gross, becoming one of the decade's most oft-quoted films and, ultimately, winning six Academy Awards, including Best Picture.

The Robert Zemeckis-directed film had a long and storied journey to the big screen, as its Oscar-winning screenwriter Eric Roth told Yahoo Entertainment during a wide-ranging interview (watch above).

"I was writing something else for Tom Hanks, which [eventually] became not a very good movie called The Postman," Roth said about his entry into Gump, referring to the 1997 post-apocalyptic adventure that ultimately starred Kevin Costner and turned into one of the decade's most infamous box-office busts. Knowing Roth and Hanks were high on collaborating, producer Wendy Finerman sent them both Winston Groom's 1986 novel Forrest Gump to see if they'd be interested in adapting and partnering on it. The rest is history.

Some other choice tidbits from the true story of Forrest Gump:

Roth toned down some of the coarser and more outrageous aspects of Groom's book. "He swore more, he had a lot of sex. It was more farcical. He was supposed to weigh about 350 pounds." In one of the most infamous footnotes from the source material, the Alabaman went to space with a male orangutan named Sue, and crash lands on an island full of cannibals (he only survives this by beating them at chess). "It was really pretty exaggerated."

Roth incorporated special effects into the screenplay that would have heightened defining aspects of his main characters. "I pushed the envelope with certain things. I had Jenny (Robin Wright) always with angels wings, which is a little much. I had Lt. Dan (Gary Sinese) always with a cloud over his head, like it's going to rain," Roth explained. "There were like 12 of those things. I think I just overwrote. I probably went too crazy, and Bob started taking back what he thought was too much."

The screenwriter consulted with friends Billy Crystal and Robin Williams with Gump's Vietnam protest speech at the Washington Monument. "[Zemeckis] never liked the speech I had Forrest Gump give when he was given the microphone at that event. He said, 'We need something that's way funnier and way more important.' Funnier I tried, and I even enlisted some comedians. I asked Billy Crystal to help me, I asked Robin, [some] other people. And nothing ever resonated. And then I tried to write some big glorious speech about patriotism and Vietnam. It was a really wonderful American speech. And that didn't quite work. So Bob came up with the solution of he starts speaking, and they pull the plug."

The filmed yet ultimately cut a scene involving Martin Luther King Jr. and the Selma protestors being attacked by dogs. "It was the very first day of shooting. Jenny and [Forrest] are walking along a bridge, they're about to go to college and bemoaning the fact that she got into college but he didn't. And they hear a bunch of noise. And they see that the Selma march is happening. It was sweet, but probably a little bit disrespect, maybe. Maybe, I don’t know. And I don't think Tom's accent was quite right, it was the first time he tried it," Roth explained. "I think we felt we went a bridge too far. We wanted to honor Martin Luther King and the march and the importance of that, obviously. So I'm glad we didn't use it."

Roth has mixed feelings about the more recent criticisms of Gump, which have called out the film for mocking its hero's mental handicap at points and the "classic mother-Madonna-whore figure" Jenny, who succumbs to a disease the screenwriter confirmed was HIV/AIDS. "Look, this was the subject matter, so I tried to make him as human as possible. Yes, I think you could say it's probably not a particularly nice portrait. … It's a nice portrait of a man, but he happens to have mental challenges, and is certainly not sophisticated in that way," Roth said. "Any criticism I've heard about her was not really fair. … I know it's a very simplistic look at things, because her father was supposed to be sexually molesting her, abusing her. I don't think it's unusual for those people to be in a lot of pain, and addiction is a very common. And in that era using various needles, you could very well get HIV. So I don't think it's untoward at all that we had die of something like that. I don't think there's a politic behind the movie. In other words, I think it reflects what you want to see in one sense, and in the other sense all the variations of what people look like in this country."

Watch: Eric Roth talks about the Forrest Gump sequel that never happened:

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