If Kazan had hired this guy to play Terry, he probably would've received a gift basket of bottles of Newman's Own Dressing. In order to convince the producers that Marlon Brando would be right for the role—and to convince Brando himself—Elia Kazan held another audition with an actor from the same school of acting ("The Method," as practiced at The Actors Studio): Paul Newman. This provoked Brando to hop onboard, and the producers to accept him. (Source)

Start spreading the news…Frank's leaving today. Originally, Sam Spiegel told Frank Sinatra he could play the role of Terry. Eventually, Kazan convinced him Sinatra wouldn't be right for the role, so they gave it to Brando. Sinatra was really ticked. (Source)

Did Sam Spiegel drive Budd Schulberg to the point of almost committing murder most foul? After agreeing to make Schulberg's screenplay, Spiegel harassed him over and over again to make changes to his script. At one point, Schulberg's wife woke up and found him shaving at 3:30 in the morning. He told her he was heading to New York to kill Sam Spiegel (probably not a serious comment). Fortunately, he didn't. (Source)

Originally, Arthur Miller—the famous playwright—wrote a script about waterfront corruption entitled "The Hook." His friend Kazan was scheduled to direct, but they couldn't get anyone to make it, and Kazan and Miller had a falling out over. (Source)

Marlon Brando had a memory lapse—a brain fart, in other words. He claimed he improvised the famous "I coulda been a contender" line—but this was totally untrue. Budd Schulberg came up with the line, and it is in the original script. But Brando did consult with Kazan, and they decided to have Brando sadly push away Charley's gun after delivering that part of the speech. So maybe he somehow confused that with coming up with one of the most famous lines in movie history... (Source)

There was a real crime-fighting super-priest behind the Father Barry character. He was actually based on Father John Corridan, who fought against waterfront corruption, while Johnny Friendly was based on a combination of mafia members involved in union corruption. (Source)