Garrett Park last week voted itself America's first nuclear-free zone, thus affirming a tradition of peacefulness that began back in 1898 when it became illegal to harm any tree or songbird within the town limits. It also was characteristic behavior for an antiestablishment community that counts as one of its finest hours its 1955 victory against a postmaster who wanted to do away with the post office boxes and institute home mail delivery in the name of greater efficiency.

Garrett Park Civic Association President Eugene McDowell termed the antinuclear ordinance "purely symbolic." That didn't stop the national and world press from invading this 123-acre Montgomery County town, where stately Victorian and Edwardian homes share the same oak and maple-shaded streets as Chevy houses, so-named because you could buy one in the early 1920s for $5,500, a price that included a two-tube built-in radio and, in the driveway, a Chevrolet. The list of visitors included everyone from the three networks to Tass, the Soviet Union's official news agency. Town Clerk Glenda Ingham, one of two paid town employes--the other is the handyman--was trying to prepare the budget, but she spent half her time talking to reporters, who telephoned from Canada to California. They kept referring to Garrett Park in their stories as tranquil, but it was hardly that.

"It's been a wild week, I'll tell you," said ex-mayor Donn Mader, who tallied nearly 30 interviews and admitted that he received more attention as ex-mayor of America's first nuclear-free zone than he ever had as mayor. Garrett Park, whose 1,200 residents include physicists, psychiatrists, high level government workers, nine published authors (the town newspaper recently ran a list) and at least one New York Times reporter, was better prepared than most places its size to meet the invaders. Mader, who is himself an operations analyst-turned cabinetmaker, handled his Tass interview with typical Garrett Park hospitality. "We sat on a bench in front of the post office and chatted for about 15 minutes."

Mader, who moved to Garrett Park in 1956 ("I saw this nice town with big trees, and I told my wife, 'I'd like to be mayor of this town someday so let's move in"), joked about the "penetrating questions" he had been asked. "One reporter asked if we're conservative or liberal. I told him, 'We're liberally conservative and conservatively liberal.' He said, 'My editor won't take that.' So I told him we like to think of ourselves as liberal on external matters and conservative on internal matters."

Seven days after Garrett Park took its symbolic step, President Reagan visited Eureka College and made arms reductions proposals that might be seen as part of the same antinuclear movement that has been so visible in the world this year. Civic Association President McDowell called Reagan's speech "a commendable, symbolic step" and a fitting ending to the first week in America's first nuclear-free zone. "It's too much to hope for quick, substantive solutions," he said. "We have to start at the symbolic level."

Garrett Park's antinuclear ordinance began with McDowell, a mild-mannered, bespectacled systems analyst at the National Oceanic and Atmospheric Administration, who studied philosophy in college, still reads Aristotle and thinks a lot about the future of the world. McDowell, 42, was an unlikely leader, his activism having been previously limited to signing his name to a nuclear freeze petition. "I was frustrated for about a year over nuclear issues," McDowell said. "I figured this was a way I could do something without any real interruption to my life. In February it seemed like a spit in the ocean."

In March, the Garrett Park Town Council unanimously approved a nuclear freeze resolution. A month later the town made the "Good Morning, America" show. It was McDowell's first network experience, and his interview with Susan King gave him a taste of what was to come. "She asked me if we were defying the federal government. I was so surprised I'm not sure what I said. I mean, I'm a civil servant, my father was, my grandfather was. The federal government is what I grew up on. It's my whole professional identity."

The ordinance that brought international attention to Garrett Park, located 14 miles north of the White House, between Kensington and Rockville, was less than controversial among the townspeople, many of whom had been attending Maryland Nuclear Arms Freeze Task Force meetings at the Cedar Lane Unitarian Church in Bethesda. "There wasn't any debate," said Barbara Shidler, Garrett Park historian and caretaker of the trees in a town that has declared itself an official arboretum. "The point is to simply say, 'Look, this thing is getting out of hand. It's time to stop and think about what the hell we're doing.' "

Among the 46 who voted against the ordinance was Ned Dolan, a retired Marine Corps captain and a former CIA intelligence officer who managed, when he was president of the Garrett Park Civic Association 22 years ago, to get all but one of the town's streets closed off ("I said, 'Well, gee, let's close the roads. We've got the power' "). Dolan, who says he opposed the ordinance because it's "an unenforceable law, and I feel very strongly about laws," was invited to give his views at an April meeting of the civic association. "I couldn't go," he said. "I had a commitment to take my wife to the dinner theatre in Burn Brae. I figured they could always get somebody else. I wasn't going to change any minds."

The ordinance is grandly worded: "The people of this town hereby declare the town of Garrett Park to be a Nuclear-Free Zone. No nuclear weapon shall be produced, transported, stored, processed, disposed of, nor used within Garrett Park. No facility, equipment, supply or substance for the production, transportation, storage, processing, disposal or use of nuclear weapons shall be allowed in Garrett Park."

Two weeks before the referendum, a group of townspeople, led by longtime pacifist Gordon Connelly, a retired Gallup pollster who was a conscientious objector during World War II and a protester during the Vietnam War, went to Washington to deliver a copy of the resolution to the White House, The Washington Post and the Soviet Embassy. "We went to the mailroom--Room 45--at the White House," Connelly said. "We left it with a clerk. They rubberstamped it "for the president's attention."

Two days before the referendum, McDowell got an inkling of what was about to happen when he ran into one of his neighbors, who happens to be married to Ben Franklin, of The New York Times. "I saw Jane, and she said, 'Ben checked. We're the first!' "

Last Monday was election day. The voters went to the post office--which they refer to as "downtown" and still visit to collect their mail, meet their friends and read the bulletin board--to cast their paper ballots for the mayor and two town council races as well as the antinuclear ordinance. Voter turnout was, as usual, high: 302 of 386 registered voters.

There was a moment of panic late that afternoon, on the same day as President Reagan's visit to the Prince George's County family that had a Ku Klux Klan cross burned on its lawn. McDowell recalled, "Glenda was listening to the radio and heard something on the news about the president going by helicopter to a little town in Maryland. We thought at first he was coming here. Someone said we should declare ourselves a chopper-free zone."

"It would have been one more distraction," said Norah Payne, circulation manager for the monthly Garrett Bugle, the chatty newspaper that is distributed free to every family in town.

That night everyone gathered at the 85-year-old town hall, with its silver maples and wooden buckets of yellow tulips on the front lawn. The hall was at its capacity--75 persons, including six camera crews. The referendum result was announced at 9:30. It passed, 245 to 46. "We were ecstatic," said Norman Modine, a retired physicist who was present when the first nuclear chain reaction was set off at the University of Chicago on Dec. 2, 1942 ("It was all downhill from there").

Garrett Park, where the biggest events in a normal year are the Fourth of July parade and the New Years Day Champagne Brunch, became an overnight international celebrity. That presented a small problem for the normally unflappable Donn Mader, who lost the mayor's job last Monday to Peggy Pratt, a librarian. "I'll tell you the question that really threw me," he said. "The Japanese reporter asked me what message I wanted to give the people of Japan. Of course, we'd never thought of giving a message to Japan. I said we hoped they would understand there were other people in the world who thought nuclear weapons were undesirable."

McDowell, who had been in the midst of revising the budget handbook for NOA, took a few days annual leave in order to accommodate reporters. "Mostly people have had a roaring good time," he said. And while he says his newfound celebrity status has not turned his head--"I don't want to be the leader of a movement, I've got to get back to normal life"--the man who started it all in Garrett Park admits to dreaming. "Churches and libraries could declare themselves nuclear free zones. Vehicles and restaurants, doctors' offices, grocery stores, banks. Private individuals could say, 'My house is a nuclear free zone . . . ' "

One person who might have been rightfully displeased with all the media attention was Jennie Rothwell, editor of the Bugle. She got scooped on one of the biggest stories in the town's 84-year history since the next issue of the Bugle doesn't come out until Friday. But Rothwell, who also has three small children to look after, said she didn't mind. She has other stories to cover, the hottest being an issue the Town Council will soon consider: Whether to raise the rent for private use of the town hall.