An interfaith group of peace activists returned to Memorial Bridge yesterday to reclaim a one-ton granite memorial impounded three months ago by U.S. Park Police and push it through downtown streets to a temporary home at Georgetown University.

About 30 men, women and children--wearing T-shirts with the image of a tombstone engraved with the words "Unknown Civilians Killed in War"--cheered as a tow truck driver lowered a caisson bearing the memorial onto the road near the entrance to Arlington National Cemetery.

"It's back on the street! Yes, indeed!" whooped Ellen Barfield, 43, an Army veteran and longtime peace advocate from Baltimore.

And onto the street they went, too, Barfield and others who call themselves Stonewalkers. They grabbed the caisson's handles, pulling the memorial and its 1,500-pound wagon across the Potomac River bridge into Washington, up 23rd Street to Washington Circle and west on M Street.

Destination: the garden of Georgetown University's Center for Peace Studies, which is housed in the university's observatory, a three-mile, 75-minute tug away.

All along the route on a beautiful fall afternoon--especially in crowded, tony Georgetown--people stopped to gawk, wave, cheer or turn their heads in inquisitive stares. "It doesn't matter what they're thinking--just that they're thinking," said Lewis Randa, 52, one of the organizers.

The Stonewalkers are members and friends of the Peace Abbey, an interfaith peace organization in Sherborn, Mass., that sponsored a slow 500-mile pilgrimage from Boston to Washington last summer. The journey took 33 days.

The goal was to erect the stone near the Tomb of the Unknowns at Arlington National Cemetery in memory of the tens of millions of civilian war dead over the centuries, Randa said.

But Congress must approve the addition of a monument at the cemetery, and lacking even a congressional sponsor, the Stonewalkers were forced to abandon their plan. They also abandoned the caisson, leaving it in the middle of Memorial Bridge on Aug. 6, the 54th anniversary of the dropping of the atomic bomb on Hiroshima.

The activists asked U.S. Park Police to take the memorial into protective custody, hoping to reclaim it once Congress approved their cause.

Three months later, the Stonewalkers still have no congressional resolution. But they do have the sympathy of the Rev. Richard McSorley, founder and director of Georgetown's Center for Peace Studies. McSorley offered to display the stone temporarily in the center's garden between the observatory and the football stadium.

The Stonewalkers hope the stone eventually can go to Arlington National Cemetery, but meantime they have a new strategy. Next summer, Randa and other Peace Abbey members will return with a refurbished caisson. They'll pull the monument to Baltimore, where it will be shipped to Northern Ireland for a peace walk from Belfast to Dublin. Then it will be displayed at Oxford University until summer 2001, and later it will go to Paris.

The idea, Randa explained, is to continue to stir up interest, especially in Europe and Asia, "where people haven't forgotten what death is. We [Americans] have."

"As long as Congress refuses to accept it, it will continue to move," Randa said.

CAPTION: Marchers take the stone and its 1,500-pound wagon across Memorial Bridge on their way to Georgetown University's Center for Peace Studies.