In 1971, Beeps Clark, Pat Jennings, and Chris Ready decided that there had to be a better way of raising money for Harvard’s League of Women Voters. “Knocking on doors for donations was a lot of effort,” and didn’t guarantee an adequate return, explained Still River resident Jennings on Monday. “Some people probably thought we were subversive” she joked, recalling the door-to-door days with a chuckle.

Thus began a new and enjoyable way of fundraising, the Columbus Day Weekend Flea Market, which will be held this year in front of the new library on Saturday, Oct. 11. The rain date is Monday, Oct. 13.

The League hosted the flea market on its own for more than 10 years before inviting the Harvard Conservation Trust to co-sponsor the event. This year, another change is in the offing: the Harvard Schools Trust has entered the partnership on a trial basis.

“Based on this year’s experience, we can decide if this is a good fundraiser for us,” said Steve Finnegan, a member of the Schools Trust Board of Directors.

Many on his board have volunteered to help, to get a sense of the event. Meanwhile, Sue Toll, a trustee for the Harvard Conservation Trust (HCT), explained last week why HCT is passing the torch.

“Our board has voted to pursue fundraising events that speak directly to our mission. We are thinking about a run on the trails or something else that gets people out on the land we are protecting,” she said. Toll herself has worked for three years as a co-chairman of the flea market, and says the Conservation Trust values the event as a great Harvard tradition.

Jennings said the flea market began as a tail-gate affair, with local people selling white elephant merchandise and school groups offering ethnic food.

“It was our chance to see everyone and we did have some times!” she said.

One of those times involved a brand-new sweater that was essentially sold off the owner’s back. Jennings recalled with fondness her friend Paula, who had rented a booth with her daughter to sell excess household items. “She wore a gorgeous, new, LL Bean sweater that day, but took it off when the weather turned warm. Her daughter innocently sold [the sweater] when Paula stepped away,” she said.

According to statistics kept by longtime flea market organizers Barbara Kemp and Sue Robbins, the flea market has grown to include more out-of-town vendors, for a total of more than 170 booths, including an aisle-long food court. Gate receipts over the past 10 years show an average attendance of 3,000 customers. Robbins said attendance bulged one year when an accident on Interstate 495 sent cars streaming off the Route 111 exit into Harvard’s center. “We had so many people, we ran out of food,” Robbins said.

Audrey Ball, executive secretary and driving force of the league, has worked continuously on the flea market since 1992, starting as chairman.

“I enjoy absolutely everything about the flea market except a rainy day,” the 42-year resident declared this week. Only once, in 2005, has the flea market been cancelled for the weather.

Another figure who looms large in the success of the flea market is Jim Wallace, who has been laying out the booths for almost 25 years. Armed with string and a fail-safe mental map, Wallace leads the same group of helpers year after year. Pete Jackson, one of that team, said his friend inspires awe with his uncanny ability to align the aisles on a dime, without measuring.

“His method is methodical, magical, and it is secret. It’s like he has a built-in global positioning system. And we are not allowed to slack.”

Jackson said that he and his wife Kathy are programmed now for the setup. “I always know where I am going to be at 4 p.m. on the Friday before the flea market,” he said. Houseguests for the long weekend simply tag along, he added. “Everyone gets a hammer and listens to Jim.”

Loyal booth-holders, such as Dottie Milanoski, have also contributed to the flea market’s success and longevity. Milanoski, who specializes in American pressed glass, has been renting space on the Bromfield playing fields for at least 15 years. She keeps a small shop at Holliston Antiques Co-op and though she sells at “a dozen shows a year,” the Harvard venue is one of her favorites.

“We just love it,” she said. “The people that come to the show are so nice. We come expecting to sell, and to buy!” Sometimes there’s a find, such as the rare, car-shaped teapot her son bought for five dollars and later sold at a handsome profit. Being at the flea market, she said, just “puts me in the fall mood.”

Flea market pioneer Jennings will not be at the flea market this year, but will instead be found on the Common, volunteering at the Congregational Church’s Apple Festival.

“I’ll be there with the apples and pies. But it’s good to know the flea market will be going on at the very same time.”