Newport, R.I., lives off its past.

Its vitality as a tourist center is largely built on memories of the days when the Vanderbilts and the Astors summered at seaside mansions awash in servants and when a party might feature swans in the fountains or monkeys in the trees.

The Gilded Age is long over, but this city still works to protect its past by preserving the mansions that attract tourists. Central to that effort has been the Preservation Society of Newport County, a well-heeled group that spends a robust $22 million a year showcasing the city’s history of extravagance.

So it’s a bit surprising that the latest contretemps there involves accusations that the society stuffed votes to win a smallish $25,000 preservation prize.

The grant, in 2011, went to help fix up the Breakers, the 70-room “cottage” once owned by the Vanderbilts. The society won the contest, held by the National Trust for Historic Preservation, by producing the most emails demonstrating public support.

But another group, the Friends of Newport Preservation, has charged that the Preservation Society of Newport County won by strong-arming its staff members to vote multiple times, by creating extra email accounts for them to use and by pushing tourists to turn over their email addresses.

“The result of all this pressure and manipulation was that one person could equal several votes,” the Friends group, which includes three Vanderbilt descendants, said in a letter of complaint to the Preservation Society last fall. “It appears that the Society got the $25,000 award using unethical means.”

In interviews, two former staff members said that they felt guilty that their organization had beaten out other projects that lacked deep pockets, including preservationists working to refurbish a historic but downtrodden section of Cincinnati.

“There were just places that would have benefited so much by the unexpected gift of $25,000,” said Caroline Considine, who oversaw development for the Preservation Society at the time. “We could have gone to a single donor. Instead, it became this convoluted approach to being dishonest about where the votes came from.”

The organization, a nonprofit that manages 11 properties in Newport, does not deny it encouraged people to vote more than once. But it pressured no one, it says, and simply competed with fervor to win the This Place Matters community challenge, in which the National Trust invited entries from preservation groups nationwide.

“We used every opportunity to promote and energize this contest within the rules,” said John G. Rodman, the Preservation Society’s director of museum experience.

In a country where ward bosses have dug up votes in cemeteries and All Star ballot stuffing is a baseball tradition, a little zealotry in pursuit of preservation can hardly be considered a sin. The National Trust says the Preservation Society played within its rules: that staff, and others, could vote more than once. But the National Trust said it had since tightened the rules on voting to tackle a different issue, one not involved here, to prevent use of automated bots.

Even those who were beaten are being good sports about it.

“I say, ‘Good on you,’” said W. Kevin Pape, board president of the Over-the-Rhine Foundation of Cincinnati, which came in third. His organization received $5,000 to help revitalize a frayed historic neighborhood there. Mr. Pape acknowledged, though, being a bit surprised that they had lost.

“We had the whole community here,” he said, “and somehow this historic house got enough votes.”

The voting dispute is just one skirmish in a wider war between the Preservation Society of Newport County and the closely named but antagonistic Friends of Newport Preservation. They have fought over issues of management and transparency in how the society is run. The bloodiest battle has been fought for years over a new visitor center planned for the Breakers’ grounds. The Preservation Society says the center is necessary to accommodate 400,000 annual visitors to the mansion. Critics say it will be an eyesore better located in a nearby parking lot.

“The leaders of the Preservation Society of Newport County are motivated by greed and money, ‘the root of all evil,’” Gloria Vanderbilt Cooper wrote in a letter to The Providence Journal this month in which she bemoaned the center plan. “They are showing little interest in preserving a part of our national heritage.”

The visitor center plan has survived several legal challenges, though, and the Preservation Society says ground will be broken soon. It said that it had investigated a variety of issues raised by the Friends — whom William R. Landry, the society’s lawyer, described as the “small but energetic opposition” — and found them to be without merit. He described the voting dispute as just another flanking maneuver in the larger fight, and noted that the contest for the grant ended some six years ago.

“They are throwing things against the wall to see if something might stick now that every other argument has been rejected,” he said.

The Preservation Society fully acknowledges that the contest fueled its competitive spirit. Yes, email addresses were created for employees who didn’t use computers at work. Of course there was a broad effort to win votes from visitors, organization members and local businesses.

“Everyone we contacted was told they could vote with both their work email addresses and any personal email addresses,” Mr. Rodman said.

The Boston Globe even joined the fight, urging readers to “rally around Newport” to keep New England from being bested by Cincinnati.

When the voting finished, the Breakers had tallied more than the Ritz Theater in Wellington, Tex., population about 2,000, which won the $10,000 second prize. The group’s chief executive, Trudy Coxe, proclaimed victory in a news release and posed alongside others with a huge mock-up of the $25,000 check.

“The depth and breadth of support we received in this endeavor was breathtaking,” Ms. Coxe said in the release. “We literally received votes from around the world.”

But Ellen Sadlier, who worked as a part-time tour guide for 11 years, said the voting tactics were one reason she left the job shortly after the contest. People who had never had Preservation Society email addresses, like groundskeepers, were given them so they could vote, she said. Visitors were corralled, she added, to lend their email addresses to the effort.

“It was more of a game in the beginning and then it got really scary,” Ms. Sadlier said. “They came up with buttons and bumper stickers. It was like it was a political campaign.”

Mary Joan Hoene, a New York lawyer and Friends member, said that her group first complained about the 2011 voting behavior in 2014. She said the Friends are finally making their objections broadly public because their initial complaints to the Preservation Society had been brushed aside.

“We are trying to expose some of that and make them feel the pressure,” she said.

The Ritz Theater and the Cincinnati foundation said that they had tried hard to win the contest, too, but that they had not coached anyone into voting multiple times.

Melanie Baumgardner, who was president of the theater board at the time, said they were thrilled just to come in second. The $10,000 grant was a lifeboat to an organization simply trying to stay afloat. And she remembered how the Newport group reached out afterward, so graciously, to congratulate the Ritz on its second-place finish.

“We got a nice letter,” she said, “saying how amazed they were that we fought so hard and that we came from such a small place.”