Stallone refused a six-figure offer unless he could play Rocky himself
Sylvester Stallone drafted Rocky in about three and a half days after watching an underdog last fifteen rounds against Muhammad Ali. Studios wanted a star such as Robert Redford in the lead. Stallone held out, the film was made for about $1 million, and it became 1976's biggest earner and a Best Picture winner.
The spark came on March 24, 1975, when Chuck Wepner survived into the 15th round against Ali before being stopped at Richfield Coliseum in Ohio. Stallone denied that Wepner inspired the script, though Wepner sued and settled for an undisclosed sum. Other possible influences include Rocky Marciano, Joe Frazier and Rocky Graziano's autobiography Somebody Up There Likes Me.
Getting it made was a fight in itself. Henry Winkler, then famous as the Fonz, took the script to ABC, which bought it for television but wanted a new writer; at Stallone's pleading, Winkler leaned on his star power to buy the rights back. United Artists liked the story yet saw it as a vehicle for someone like Burt Reynolds or James Caan, and Stallone's agents issued an ultimatum. Producers Irwin Winkler and Robert Chartoff could greenlight cheap projects, so the budget was held to $1,075,000.
Casting ran late. Boxer Ken Norton was first choice for Apollo Creed before Carl Weathers took it, and the Adrian role passed through Carrie Snodgress, Susan Sarandon and Cher before Talia Shire won the producers over. Economy showed everywhere: Stallone's father rang the round bell and his brother appeared as a street singer. Joe Frazier, who makes a cameo, claimed the meat-punching and museum-steps scenes came from his own training without credit.
In the story, Apollo picks an unknown Philadelphia southpaw for a Bicentennial title fight largely because the nickname Italian Stallion sells well. Rocky loses on a split decision but goes the full distance, which is all he wanted. Released in December 1976, the film took about $225 million worldwide, won three of its ten Oscar nominations, and joined the National Film Registry in 2006. At the Oscars, Ali joked onstage that he was the real Apollo Creed.
Source: Rocky
