"The first time I met him I was 18," said Wahlberg. "I was just starting my music career. He hadn't fought the big fights yet but he was already a local legend."
Wahlberg lived with the project for years until all the pieces finally came together.
Christian Bale plays his brother, Dicky. He was impressed with Wahlberg, not only as an actor, but also as a producer.
"He had passion for this movie and it always makes a big difference when you have someone who's not just treating it like a gig," said Bale. "You can tell those people a mile off."
"Everybody was into it, and that all starts from Mark, who's been wanting to make this, been his passion project for years," said Bale. "Five years the guy's been in the ring training. Sounds crazy but he got it done."
And while there is a boxing theme to the story of the Ward brothers, co-star Amy Adams says it's really about so much more.
"It is story about family, struggle, but it's fun, funnier than you expect," said Adams. "Christian is transformative. Mark does an amazing job. And Melissa [Leo] is a force of nature. In this film, I think there's a lot for people to enjoy."
"The Fighter" is in limited release now, but punches its way into more theaters this weekend.