More than 5,000 New Englanders from 11 Connecticut townships rallied in an atmosphere of musket smoke and memory today for that rarest of U.S. bicentennial occasions: the full-blown historical reenactment of a calamitous American defeat.

Storming the grass-covered ramparts of Ft. Griswold here, 450 costumed Redcoats overwhelmed and symbolically butchered a Colonial garrison to the cheers of crowds of camera-snapping spectators on the sidelines.

Fought just a month before Yorktown amid currents of confusion and treachery, the battle of Groton Heights was one of the Revolution's last and bloodiest and ultimately decided nothing but the lives of those who fell.

But for their descendants in the centuries since, it has become a curiously poignant symbol of American sacrifice and valor and of the enduring price of American liberty.

"Only one male member of Groton Congregational Church was left alive after the battle," said Mary Virginia Gordon, an 86-year-old area historian. "That was my ancestor Solomon Morgan; he was too old to fight.

"But there were 40 widows. Just imagine the cost."

"History is important," Connecticut Attorney General Carl R. Ajello told a descendants dinner of about 250 Friday night. "If you don't know where you've been, you damn sure don't know where you're going."

The only major Revolutionary battle in Connecticut, the battle of Groton Heights has been refought every year since 1975 with a maximum of public participation and a minimum of commercial hoopla.

In addition, this year, the Redcoats symbolically burned New London across the Thames River, whose waters, filled today by nuclear submarines, once sheltered American privateers.

It was the privateers' harassment of ships supplying the British Army which brought on the battle 200 years ago today.

The British hoped by sacking Groton and New London and seizing storehouses of supplies to interrupt the flow of food and ammunition from Connecticut to Washington's Continental Army in Virginia, and to burn "the rebel pirate ships" as well.

Ft. Griswold, commanding the Groton and New London harbors, prevented direct naval assault.

But the British, under command of turncoat Gen. Benedict Arnold, landed downstream and attacked overland from the rear of the fort, behind its heaviest guns.

There were also cryptographic problems.

When Sgt. Rufus Avery spotted the British ships approaching at sunrise, he ordered two cannon shots fired to signal Colonial reserves to rally to Ft. Griswold's defense.

But Arnold, from nearby Norwich, knew the signal, and fired a third cannon, leading many colonists to believe the shots signaled only the capture of another British ship.

Finally garrisoned by only 150 men under Col. William Ledyard, the colonists found themselves heavily outmanned and ordered to surrender or face no quarter.

Ledyard, however, expected reinforcements at any moment and elected to hold.

"We will not give up the fort," he said. "Let the consequences be what they may."

Forty minutes of furious fighting later, an errant shot carried away the colonists' flag, leading the British to believe the Americans had surrendered. The colonists, however, kept on firing, confirming British suspicions that the Americans were ungentlemanly and heedless of the rules of war.

When the Americans finally did surrender, after the British had breeched the gates, the infuriated Redcoats shot or bayoneted the survivors and ran Ledyard through with his own sword.

Nearly all of New London was destroyed during the day. Although only three Americans died during the battle, 85 were killed or mutilated after they surrendered and another 63 were wounded or taken prisoner by the British.

A wagonload of wounded hauled off by the British rolled out of control down a hill, crashing into a house whose floors became soaked with blood.

Part of the reason the battle of Groton stays alive is the Avery Memorial Association, an organization of descendants of a populous Groton clan, 15 of whose members died at Ft. Griswold, and 140 of whom showed up Saturday for the organization's 86th annual meeting.

Now scattered from coast to coast and border to border, the Avery descendants range from the millionaire Rockefellers to the local town policemen and delight as much in the frailties of their forebears as in their achievements.

The society's cheerfully irreverent newsletter recently detailed the Falstaffian adventures of Christopher Avery, the family progenitor, who was tried in court at age 65 for drunken partying with another man's wife aboard an anchored ship off Massachusetts in the 1600s.

Also recounted was the tale of Ephraim Avery, a philandering clergyman whose celebrated 1833 murder trial (he was acquitted) inspired Nathaniel Hawthorne's tale, The Scarlet Letter.

The battle of Groton Heights won't let the Averys go.

At Saturday's meeting, Shep Matheson, 17, told how a search for a high school term paper topic had led him to Ft. Griswold where he remembered a vague family rumor of an ancestor who had once fought a battle there. He didn't know when.

The paper in turn led through a genealogist's nightmare of mingled bloodlines, thrice-married widowers and multiple generations with the same first name to his great-great-great-great-great grandfather named Jasper Avery who had died on Groton Heights.

That led him to other relatives like Thankful Avery and Freelove Avery and to the battle itself. There he learned of the Avery with his skull hacked open in the fighting, who, carried off as a corpse awoke to murmur, "Keep step, damn you boys, you shake me so." He lived into his 80s.

And the other battle survivor who, after a bullet had passed through his chest, kept it for years as a bitter reminder until an unknowing nephew lost it while using it as a sinker on a fishing line.

"It was kind of exciting," said Matheson, a senior at Loomis Chaffee school in Windsor, Conn. "All this from an unknown ancestor."

But even those without revolutionary ancestors find their ties to the battle. Eugene Gumbs, 42, of New London, reenactment coordinator for last weekend's program, said his ancestors were still in France and Russia a century after the Battle of Groton Heights. But that does not matter.

"We can't let this die," he said. "It's not celebrating a defeat, it's explaining what people of this area did for us, for all of us, 200 years ago. It's what they gave.

"I mean we were hitting up a bank here in town for contributions and they wouldn't give a dime. We tried several times. Nothing. Then one of our girls called them up and said, 'Listen, if it wasn't for those guys in the Revolution you'd be the Bank of England.' We got $100. See what I mean?"