One of the last ones to board was Bush's national finance chairman, New York Jets owner Woody Johnson, carrying a white visor with the team's green logo.
Admiring a green sweater slung over the shoulders of a fellow donor, Johnson said: "You can never have too much green."
The confab for some of the GOP's wealthiest donors came as Bush's campaign and an allied super PAC announced that they had raised more than $114 million to support the former Florida governor - an unprecedented sum in American politics that gives Bush a sizable financial advantage over more than a dozen GOP rivals and over Democratic front-runner Hillary Rodham Clinton.
Bush had announced plans for the Kennebunkport donor retreat at the start of his campaign, dangling one of the choicest chits in Republican politics - a visit to his family's beachfront estate - as an incentive to benefactors. Supporters who gave the maximum $2,700 to Bush's primary campaign, and who were able to find at least 10 other people also willing to do so, were
invited to attend.
While campaigning in New Hampshire on Wednesday, Bush was asked by reporters why he had decided to hold the retreat at his parents' estate, known as Walker's Point. "It's at the Colony, it's not at my parents' home," he said, referring to a local hotel. "That would be a little overwhelming for them."
But former president George H.W. Bush and his wife, Barbara, didn't seem to mind all the fuss.
The stately Colony Hotel is where most guests stayed and where a closed-door briefing was held on Friday. But on Thursday evening, the family compound at Walker's Point was the main venue.
The festivities began at the hotel's Carriage House, where attendees boarded the trolleys with about half a dozen Secret Service agents looking on. Once on the grounds of the estate, the former president and first lady greeted the guests and led them across the compound to their home on the southern tip of the peninsula.
Elated at the invitation, some attendees quickly posted photos on social media.
"Incredible night in Kennebunkport!" Fritz Brogan, a Washington-based donor and former aide to Jeb Bush when he was governor, wrote on Facebook as he posted a photo of himself alongside George H.W. Bush.
Reporters were not allowed to attend the dinner but could easily watch the proceedings from a public overlook about 1,200 yards to the west, where tourists and locals often gawk at the property.
Around 5:30 p.m., Jeb Bush was spotted entering his parents' home and came out a few minutes later, dressed in a blue sweater, to greet his donors. The party posed for a photo on the western lawn of the home around 6 p.m. Several attendees held campaign signs aloft as a photographer took shots of the crowd. Barbara Bush stood in the front wearing a bright coral sweater.
After that, the crowd was transported to the nearby Hidden Pond luxury resort. The mood was celebratory as donors dined on lobster rolls and hamburgers and Bush touted their record-breaking fundraising effort. His wife, Columba, smiled proudly.
"Money is great, but votes matter a lot more. I will outwork everybody," Bush said, according to attendees who asked to remain anonymous because guests were requested not to discuss details.
Back at the Colony on Friday morning, the donors were issued a new mandate: "Eight in Eight." Top bundlers who can persuade at least eight more people to donate the maximum amount by August - the eighth month of the year - will be invited to a campaign-sponsored party on Aug. 6 in Cleveland, the site of the first Republican presidential debate, and another private meeting in Miami. Several attendees, who asked for anonymity because they weren't authorized to speak publicly about the plans, said that the campaign plans to continue using short-term contests to keep bundlers motivated over the course of the campaign.
Details of the new contest came on Friday during an almost three-hour closed-door briefing attended by Jeb Bush, his parents and his son, Texas Land Commissioner George P. Bush. The session was led by campaign manager Danny Diaz, top strategist Sally Bradshaw and finance chief Heather Larrison.
Two donors said that Bush excused himself early from the meeting, telling the crowd that he had to meet with aides to begin preparing for the upcoming debate. Campaign aides declined to comment on details of the meetings.
The exclusive event had locals buzzing on Thursday and Friday amid word of increased activity at the Bush home.
On Thursday night as donors mingled on the lawn of the compound, tourists at a nearby public lookout watched on, unaware of why such a large crowd had gathered.
"They didn't invite us," quipped a woman who declined to give her name, but said she grew up in Kennebunkport and was visiting from Seattle.
As trolleys full of donors kept going past, she turned to her daughter-in-law and said: "Those are trolleys full of Republicans. Because usually they never let trolleys in there."
Another man watching the reception unfold marveled at the scene: "Every time I come here I think: There's two people who spend time over there who know the contents of what's in Area 51."
Tom Hamburger and Matea Gold contributed from Washington.