They won't watch legacy slip away

You'd have to be a local, or be really close to one, to know Sullivan's bar.

It's tucked away off Union Street. There's no sign on its brown exterior, and it's not listed in the current phone book. An Internet search pops up a different address, on adjacent Main Street. But that's the ''New Sully's," owned by a different side of the same family in the better-known locale.

This is the ''Old Sully's," a lost watering hole near the Community College Station T stop that's more like a clubhouse than a pub, and so discreet, it's known primarily to the Irish it has been serving since its speakeasy days during Prohibition.

It's here, huddled around pints of beer in its wood-paneled backroom, that a group of three lifelong residents began seven years ago plotting a documentary titled, ''The Green Square Mile," a history of the Irish who have occupied the nearly 580 acres, or not quite one square mile, called Charlestown.

The demographic changes that have rippled through Charlestown over the past years give a sense of urgency to completing the documentary, says Maureen McNamara, a Cambridge-based filmmaker tapped in November by the Charlestown Historical Society's president, Arthur Hurley, chief researcher Ed Callahan, and financial manager Jimmy Walsh to shoot the film.

''The modern situation here in Charlestown is that children that grew up here can't afford to stay here because of property values," she said in a recent interview at Sullivan's. ''The population has diminished, and it's hard to hold onto that identity."

The days are gone when everybody knew your name -- or at least your mother's.

''That would scare you -- when a woman on the street yells out to you, 'I know your mother,' that means she's going to call your mother, and you're in trouble," Hurley said.

Charlestown has had a dominant Irish presence since the group's population doubled in the 1830s, when the neighborhood was still an independent town. But beyond capturing that character, said Callahan, the narrator and key organizer, there's another driving force for the film.

''First and foremost, we want to set the record straight -- that there is a real positive story here that has never been told."

There's plenty of story to be told, word-of-mouth tales that have been passed around the town and the bar for generations: the Catholic Church's founding of St. Mary's, the second church in the Boston Archdiocese, in Charlestown in 1828; a young John F. Kennedy being led through the streets of Charlestown by a billy goat while campaigning in 1946 for a seat in Congress; and the war heroes and sports stars who emerged from Charlestown, such as NFL Hall of Fame defensive end Howie Long and 1980 US hockey gold medal winner Jack O'Callahan.

McNamara said she hopes to get Long and O'Callahan, along with celebrities including comedian Denis Leary, to speak in the film.

But the film won't overlook the neighborhood's grittier history. Callahan says the group plans to show the community, warts and all, from the busing crisis in the '70s to its current ''gangster-ridden" image, as Callahan describes it.

The group has completed a nearly 10-minute trailer to send to prospective donors, hoping to raise the necessary funds to finish the film by June and possibly print an accompanying book. McNamara plans to try to broadcast the film either locally or on the History Channel or PBS and sell copies in Charlestown's Bunker Hill Museum. The trailer cost about $11,000 to produce, and the film is expected to cost about $50,000 more to complete. So far, fund-raisers have received donations from several high-ranking Bostonians, including a $7,500 grant from the Baxter Trust Fund, care of Mayor Thomas Menino.

Proceeds from the film will go toward establishing a memorial at St. Francis de Sales Cemetery on Bunker Hill Street for the children who died in 1847 seeking refuge in Charlestown while fleeing the potato famine in Ireland.

While finding money has halted progress for now, condensing more than 175 years of history into a 50-minute documentary looks to be the biggest challenge. Nonetheless, the goal of preserving the memory and identity of the Irish in a community from which they are rapidly disappearing keeps the filmmakers motivated.

This project, Walsh said, ''will inform our kids, our grandchildren, our great-grandchildren, that at one time, there was someplace special that we called Charlestown."