Irish writer and director Jim Sheridan has a track record of making tremendously powerful films based on real-life events--films like My Left Foot, that burst forth from a core of earnestly realized human relationships. Now, Sheridan, with the help of daughters Naomi and Kirsten, has delved into the real events of his own past and created In America, a potted history of his young family's migration to New York City from Dublin in the 1980s. It is a film every bit as moving as any of the Irishman's previous work. Amidst this candid reminiscing, Sheridan and daughters transform In America into an involving family drama cum modern fairy tale, magical enough to draw comparisons with the films of Frank Capra.

The story unfolds through the narration and camcorder diaries of Christy (Sarah Bolger), big sister to Ariel (Bolger's real-life sister, Emma) and eldest daughter of Johnny and Sarah. It's through Christy that we first learn about Frankie, the brother she lost to a tragic accident in Ireland, who she believes grants her wishes. The death casts a pall over this once-happy family. As Christy and Ariel, the Bolger sisters are a revelation. Wide eyes and angelic faces greet the bright lights and tall buildings of Manhattan, and they are uninhibited, eccentric and soberingly insightful as only the innocent children of loving families can be.

Paddy Considine and Samantha Morton play Johnny and Sarah, the girls' free-spirited, bohemian parents, waylaid in reality by grief. They seem ill-equipped to cope with the loss of a child, resembling children themselves. But Sheridan's actors always find real power in his writing, and both Considine and Morton exude emotion in every scene as they wrestle with making a new, happy life. Johnny, a struggling actor, is a clownish, loving family man, frozen by the loss of his son, something that inhibits his acting, alienates his wife and undermines his faith: "I asked [God] to take me instead of him and he took the both of us. And look what he left in my place. I'm a fucking ghost."

A story of such emotion that moves towards a cathartic, happy ending, will inevitably flirt with sentimentality. The family's easy relationships with neighbors who are thieves, junkies and prostitutes are too good to be true, and an '80s, ghettoized Harlem becomes an idealized playground for the two young girls. The family befriends Mateo, a neighbor in terminal decline with AIDS, played by Djimon Hounsou. Though the message he delivers to Johnny, that the life we have must be cherished, is a little saccharine, it provides the catalyst for the salvation of this hero and his ultimately hopeful young family.

Perhaps In America is made more resonant by its roots in reality. There is an acute discomfort to witnessing the very painful and private grieving of a family, with only dramatic presentation as insulation. Every word of the script Jim Sheridan wrote with his two daughters seems forged from actual memory. The performances are equally genuine. Watching almost seems insensitive and invasive, as if at any minute you might be asked to leave the room.

However, Jim Sheridan did not lose a son named Frankie. Naomi and Kirsten Sheridan did not lose a brother. Frankie was, in fact, the brother Sheridan lost as a boy. Sheridan transforms him into a conceit, worked into the biopic history of his own family to give In America its emotional anchor. This manipulation reminds us of what film can make us feel, and how truth can be synthesized so that we can lose ourselves completely in a movie and emerge feeling saddened, uplifted and changed. Sheridan has taken collected family memoirs and made them into so much more, manipulating acutely personal stories into a narrative of universal appeal. Jim Sheridan is a writer, director and storyteller who passionately explores difficult emotional truths. Thankfully, he never allows the truth to get in the way of a good story.

In America

Rated PG-13

Opens Friday, Dec. 12. Fox Tower.

Jim Sheridan directed In the Name of the Father and My Left Foot, which earned Daniel Day-Lewis and Brenda Fricker Oscars.