The title of Jim Sheridan's In America has a vaguely mythic, period-piece ring that primes you to expect an immigrant saga from generations past. That prospect is dispelled the moment we meet Johnny and Sarah (Paddy Considine and Samantha Morton), an eager, nervous pair of Irish émigrés who are crossing the Canadian border along with their two lovely, pert-nosed daughters, one of whom, 10-year-old Christy (Sarah Bolger), wields a telltale red camcorder. Arriving in New York, they drive around to the exultant pulse of ''Do You Believe in Magic'' and the magic is very much that of the new Times Square -- stock tickers and zillion-watt logos, all glistening in the night as if just for them.
The exhilaration doesn't last long. Johnny and Sarah have arranged, through connections, to rent what turns out to be the scuzziest home imaginable: a barren tenement flat in what's essentially a flophouse for junkies. The elevator is busted, the halls filled with graffiti and the apparently routine sound of one of the tenants screaming. Still, as they move in, it's with a spirit of cautious optimism. They give the place a funky paint job, and as the swelter of summer arrives, Johnny returns to midtown, this time to purchase an ancient, clunky air conditioner that he hauls, block by block, all the way back to the apartment.
How, exactly, does this family mean to survive? Johnny, played by the gifted Considine (''24 Hour Party People'') as a chivalrous yet fretful man with deeply concealed wounds, has a scattershot plan to make it as an actor, but he gets nowhere at auditions. Sheridan, the piercing Irish humanist who made ''My Left Foot'' and ''In the Name of the Father,'' is telling a story based, in part, on his own life (his daughters, Naomi and Kirsten, collaborated on the script), and he stages it with a deft specificity and understatement. There are moments that speak emotional volumes, like Christy and her little sister, Ariel (played by the actress' real-life sister, Emma Bolger), humiliated at Halloween when they're the only ones to show up at school with homemade costumes, or the positively galvanizing scene in which Johnny risks every dollar they have to win an E.T. doll at a carnival, gambling his money because his identity as a provider is on the line.
Having loved Sheridan's work in the past, however, I can't help but feel something is missing from ''In America.'' Johnny and Sarah, we learn, lost a toddler son back in Ireland, and the film is haunted by this tragedy to the point that it blots out everything else. No one in the family forms so much as a casual acquaintance on the outside, and their isolation feels hermetic and overly programmed. Actually, there's one other major character: Mateo (Djimon Hounsou), a raging painter with AIDS and a heart of gold whose apparent purpose in life, apart from splattering canvases with his blood, is to provide therapy for this family. He's Sheridan's unfortunate, if artier, version of the black saints in ''The Green Mile'' and ''The Legend of Bagger Vance.'' ''In America'' has moments of biting tenderness, yet the movie made me wish that Sheridan had let in more of America.