I Am Sam is proof that all you need to get your script made is passion and truth: that is what attracted the producers of 'Shakespeare in Love' and 'Traffic', as well as actors Sean Penn and Michelle Pfeiffer to the project.

"The script was impressively truthful and faced up to the reality of a man like Sam and what it means for him to try to raise a child. It didn't shrink from the hard questions." says Marshall Herskovitz, producer and one of the co-founders of the Bedford Falls Company (producers of such recent Academy Award-winning films as Shakespeare in Love and Traffic).

"This story is about the creation of a very unusual family, which is something we're always interested in," notes Edward Zwick.

"The script really resonated with me and touched me as a parent," says Sean Penn, who signed on as Sam, a mentally challenged single-parent who has to fight the system to not lose custody over his 8-year-old daughter. "The thing to me is that Sam's disability doesn't in any way diminish his individuality or his humanity," says Penn.

"I'm fascinated by what makes a family and how people create that in untraditional ways," says director and co-screenwriter Jessie Nelson. "I think all parents at times feel confused and overwhelmed. It is a common bond between every parent on the planet, whether you're disabled or not. Parents who are disabled provide a unique metaphor for how we're all trying to get through an incredibly challenging world and how we all ultimately need some type of support system."

While writing the screenplay, director/co-screenwriter Jessie Nelson and co-screenwriter Kristine Johnson made extensive visits to Los Angeles-based L.A. Goal, a non-profit organisation founded in 1969 that serves adults with developmental disabilities. They focused particularly on mentally-challenged parents. "They were so non-judgmental," recalls Nelson. "They were proud of every accomplishment." Adds Johnson, "I know that many of the people we met had a lot of pain in their lives, but they were very open with us and had so much integrity as human beings."

The journey to find the right actor to portray Sam began and ended in Milan, Italy, where Jessie Nelson was vacationing with her family while at the same time Sean Penn, who had recently read the script, was working on another film. "Sean hadn't formally committed yet, we were sort of circling each other, and while he was telling me about an idea he had for a scene, he stood up for a second and walked as Sam," Nelson recalls. "I thought to myself, 'Oh my God, this is too good to be true.' In that moment and in that walk I was able to see the whole movie so clearly."

Nelson felt that she had an actor who could bring the unique character to life in a completely original and authentic manner. "I knew how deep Sean could go and how meticulously he searches for the truth of a character," states the director. "To me he's the most brilliant actor of his generation. From the moment he came aboard, I feel like it elevated the whole project."

Penn's involvement in the project brought him and the filmmakers back to L.A. Goal. "When Sean got there he disappeared into the center and immersed himself in the experience," recalls screenwriter Johnson. "He didn't bring any ego with him. He was there to discover and learn."

"I wanted to go there to observe and be around people who face the kinds of challenges that the character of Sam encounters in the story," Penn says. "I have a relative with Down syndrome, but I hadn't spent any social time with other men of my age who were mentally disabled. There was an increasing comfort level in both directions with each visit to L.A. Goal, as we began to realise that there's just not that many really big differences between us about the important things in life."

Nelson, who had previously worked with Michelle Pfeiffer when she co-wrote the screenplay for The Story of Us, had the acclaimed actress in mind from the start for the role of  the high-powered, high-strung attorney who becomes Sam's counterpart in his quest to reclaim his daughter. Like Penn, whom Pfeiffer had attended the same acting class with twenty years before, Pfeiffer found herself profoundly moved by the story. "Stories about family and what defines a parent really resonate with me," says Pfeiffer. "But I was a little nervous about the character. Rita is so self-obsessed and busy that it takes her ten minutes into the scene to even realise that Sam is mentally challenged in some way."

The filmmakers were next faced with the challenge of finding a young actress who had intellectual and emotional maturity beyond her years while still retaining the innocence and vulnerability of a child. They found Lucy Diamond in virtual unknown Dakota Fanning, who has a relative that is similar to Sam's character, and enabled her to bring a certain empathy and dimension to her character.

While writing the script, Nelson and Johnson based the roles on the characteristics of Brad Allan Silverman and Joseph Rosenberg, two long-standing members of L.A. Goal. So, it only seemed natural to the filmmakers to cast the two individuals as the characters in the film.

"I had always wanted to have real disabled actors in the movie, but I also wanted the right people for the role," explains Nelson. "Brad and Joe are such wonderful actors that it wasn't as if we had disabled people who were acting; we had actors that happened to be disabled."

"I knew that the film would be significantly enhanced by their presence because the whole film grew out of our experiences with them. It was so evident that they were meant to be part of it," Nelson notes.

The Beatles play a prominent role in I Am Sam, from Sam naming his daughter Lucy Diamond after the song "Lucy in the Sky with Diamonds," to his obsessive knowledge of dates, times and places of Beatles events, facts and trivia. The permanence and timelessness of Beatles music became apparent to director/co-writer Jessie Nelson and co-writer Kristine Johnson in their research while writing the script and became a common thread throughout the film. Nelson played Beatles music on the set throughout production to keep their feel in the actors' heads.

The filmmakers agreed they'd not only assembled a dream cast in terms of actors, they also felt everyone shared a passion for the project. "For everyone, this was a journey about doing great work and we are blessed to have these people in the film," says producer Richard Solomon.