'Fifth of July,' by Sag Harbor's Lanford Wilson

'Fifth of July." There's something post- patriotic about the title. Vietnam was like that for those who opposed the war. Even for many who fought in country.

In a time of parallel post-9/11 wars, to ask why may seem unfathomable. But on July 4, 1977, and the morning after, you'll forgive a onetime "commune" of radicals as they gather to spread the ashes of Kenneth Talley Jr.'s uncle.

Inspired by a writing student of Lanford Wilson's who lost both legs in Vietnam, "Fifth of July" completed a trilogy, the first of which, "Talley's Folly," won a Pulitzer Prize. Wilson, originally from Lebanon, Mo., where the story takes place, received a hero's ovation in his adopted Sag Harbor hometown when introduced before Saturday's opening at Bay Street.

As the lights go up, we're unaware of Kenneth's sacrifice. He's seated at his desk in the Civil War-era Talley farmhouse, re-created in such faded glory by Tony winner David Gallo, a Port Jefferson native, as to make it a character with unspoken lines. (Night-to-day lighting by David Weiner and period costumes by Sarah Holden set the mood.)

As his lover Jed helps him out of his seat - that Kenneth is gay is refreshingly beside the point - we see that he's a paraplegic. Kenneth's hosting a houseful of guests: ex-roommates from Berkeley, John and Gwen, now married; sister June and her arty 13-year-old daughter, Shirley; and Aunt Sally, who's dreaded this day of finality.

John, however, has a separate agenda. His copper-heiress wife fancies herself a singer. He offers to buy the Talley estate and turn it into a recording studio. Kenneth, a teacher now leery of facing his students as a freak, is ready to sell. He covets the anonymity of world travel. But Jed, who's begun planting a formal garden, wants the farm to be their home for good.

Anson Mount as Kenneth holds life at arm's length with an acerbic wit deployed like a fencing foil. Kellie Overbey as his sister throws up her arms over the bratty antics of her (and John's) daughter, engagingly narcissistic as played by Kally Duling. (Parents who have survived having teens will nod knowingly.) Jennifer Mudge plays Gwen as a wounded diva while David Wilson Barnes' John exhibits guilt that only he fails to notice. Shane McRae's Jed is a hunky caregiver who's nobody's fool. As widow Sally, Elizabeth Franz dispenses folk wisdom in pithy sound bites, contrasting Danny Deferrari's burnt-out musician who, in what's now a cliche, can't remember squat.

Steppenwolf Theater co-founder Terry Kinney brings it all into semi-coherence. (It wouldn't be a post-'60s piece with total coherence.)

In "Fifth of July," the only war still being waged is among friends, lovers and family.

WHAT "Fifth of July" by Lanford Wilson

WHEN | WHERE Through Aug. 1 at Bay Street Theatre, Long Wharf, Sag Harbor

INFO $55-$65, baystreet .org, 631-725-9500