PORTLAND — The Gentlemen of the Road came calling Saturday, and Portland proved itself a worthy and able host.

The city’s Eastern Promenade became a sprawling landing site for more than 15,000 music fans, who turned out on a perfect summer day for the “Gentlemen of the Road Stopover,” a traveling festival headlined by the popular British folk-rock band Mumford & Sons. Seven other bands also performed, including Boston’s Dropkick Murphys.

Fans spread themselves out on the steep, grassy hillside, with two side-by-side stages near the bottom. Dozens of boats moored in the harbor, offering an idyllic background. Houses along the promenade hung British and American flags and other banners, including one that proclaimed Maine’s love of all things Mumford. Residents hosted parties on rooftop decks.

“This is absolutely beautiful,” said Brenna Pollak, 23, of Cumberland. “We need more outdoor concerts in Maine, and this is a perfect site. You have to go to Boston or New Hampshire for outdoor concerts. I hope they keep this up.”

Fans began lining up in the early morning hours for a prime spot at the sold-out general admission concert on the lawn. Music began at 2 p.m. and lasted until after 9 p.m. Mumford & Sons, the day’s final act, went on at 7:45 p.m. The long-awaited Mumford moment began quietly, with Marcus Mumford welcoming the crowd with a hushed greeting: “Good evening.”

Two video screens projected images of the show to fans in the farthest reaches of the park, but it’s hard to imagine fans atop the hill felt very close to the band.

The party continued into the night and early morning Sunday, with after-show events at clubs throughout downtown Portland, including a full set by the Dropkick Murphys at the State Theatre.

Other musicians from the festival, including members of Mumford & Sons, also attended various after-concert parties.

Portland police said no problems were reported, either during the event or as the crowd streamed off Munjoy Hill and into the city after the show.

Traffic on Congress Street was heavy after the show ended at about 9 p.m. and sidewalks were packed with people looking for clubs or a place to eat.

Police estimated the total crowd in and outside the venue at more than 20,000.

Portland Mayor Michael Brennan, who presented Mumford & Sons the key to the city, gave the festival high grades Saturday.

“This is exactly the type of event we have to have in Portland,” Brennan said. “It showcases everything we like about Portland, the Eastern Prom, the waterfront; and people are obviously having a good time.”

The festival attracted fans from across the Northeast and the Canadian Maritimes. Rachael Moore, 21, drove up Saturday morning from her home in North Reading, Mass., with friends Lindsy and Carly Goldberg. The Goldberg sisters attended the Newport Folk Festival in Rhode Island last week, and said the festival site on the Eastern Prom reminded them of Newport.

“Mumford & Sons is one of my favorite bands,” Moore said. “The fact that they are doing this festival with all these other bands is really cool. I thought it would be worth it to drive up.”

Saturday was the young women’s first trip to Portland. They were pleased to find people friendly and helpful.

“We didn’t know where the Eastern Prom was. We had our phones out, and people came up to us asking, ‘Can I help?’ People were offering to help without us having to ask. That’s pretty cool,” Carly Goldberg said.

They brought $160, and planned to spend it all before leaving – except for turnpike tolls on the way home.

There were more than a dozen food and drink vendors, all local, offering everything from cupcakes and fried dough to more healthful tofu, burritos, locally grown oysters and lobster rolls.

The vendors set up at the top of the hill, looking over the festival site from the top down.

“This is a great opportunity to come see a show and be a part of something special,” said Michael McAllister of Portland. He and his business partner, Juliet Totten, operate a vending business known as Cabin Cove. It’s a part-time concern for McAllister, whose day job is practicing law.

This is their second year in the vending business. They worked with a crew of seven, selling lobster rolls for $15 and oysters harvested from the Damariscotta River at six for $15 or $25 for a dozen.

“This is a great setup,” McAllister said. “Our view of the stage is half-blocked, but we can see the water. I’m impressed.”

Fans grew restless with the long lines as the day wore on. By 4 p.m., the food lines were as much as 90 minutes long, and hundreds of people deep. The lines for the portable restrooms were better, but grew worse as day turned to evening. Paramedics reported few issues, other than a few slips and falls.

There was free drinking water on site as well as misting tents, where fans could find respite from sun and temperatures in the low 80s. A few clouds moved in from the west by late afternoon, cooling things off briefly, but the sun came out again late in the day, baking the masses.

By late afternoon, emcee Reggie Watts asked fans to roll up their blankets and make room for the full contingent of fans streaming through the gate.

Within the fences of the concert site hung flags and festive banners, many of them sporting a motif of top hats and fancy mustaches, befitting of the festival name “Gentlemen of the Road.” At the main gate, ticket readers offered up to 8,000 fake black mustaches. Many fans wore them, and some showed up with their own top hats. Festival workers and volunteers also wore top hats.

“Being that this is the ‘Gentlemen of the Road’ festival, the top hat is right up the alley,” said Brian McGregor of Boston, a 2004 graduate of Bowdoin College in Brunswick, who sported a real waxed mustache. “It suggests class and sophistication.”

As part of their tickets, fans were given a cardboard passport-like booklet. It included a hologram with a logo of the Portland Stopover, featuring an icon of a lighthouse.

Mumford & Sons are on a major U.S. tour, but their “Gentlemen of the Road” stopovers – daylong festivals featuring many bands – are happening in only four U.S. cities. Fans got their passports stamped, and those following the band to other stopovers can collect stamps from other cities. Portland was the first of four stops.

“It’s nice to see they’ve personalized it. It doesn’t feel like just another stop on the tour,” said Pollak, the fan from Cumberland.

“Mumford & Sons is my favorite band, by far,” said 21-year-old Philip Sears of Auburn, who had just gotten his passport stamped.

Sears waited in line for 12 hours to buy tickets to the show. A music buff who prides himself “on listening to bands that nobody else listens to,” Sears said he related to Mumford’s music the first time he heard their debut CD, “Sigh No More,” in 2010.

The band sings about love – love of women, love of God – and all the hurt and complications that come with both.

“Those are themes that we can all relate to,” he said. “I’ve never felt more emotion than listening to Mumford & Sons.”

Promoter Lauren Wayne made a pitch directly to the band to come to Portland, citing the city’s culture, history and active music scene. Not only did the band say yes, it responded in kind, spending several days in the city.

It played a free, four-song set at Bull Moose Music in Scarborough on Friday, and on Friday night, lead vocalist Marcus Mumford ate a lobster dinner at J’s Oyster House.

In an effort to reach out to residents on the Eastern Prom, the band hosted a contest for the best-decorated home.

Wayne said she was pleased with how well the festival went. She plans to meet with city officials this week to talk about the festival and raise the subject of another one.

“We’ll have a pow-wow and go over what could be improved. We’ll talk about the vendor issues and the long lines,” Wayne said. “But really, there have been no major issues, and we’d love to do it again. It’s a beautiful site, and people seem to really be enjoying themselves.”

Portland has hosted outdoor concerts in recent years – at the Maine State Pier and Ocean Gateway. The Eastern Prom is far more attractive, Wayne said.

“The view is better, for one thing. Just look at the boats. It’s beautiful. But I think people also appreciate sitting on grass instead of concrete. The park forms a natural amphitheater, and it’s just much more comfortable,” she said.

Kathryn Savasuk, 23, agreed.

“Portland is the most awesome city,” she said. “I’m from here. I live in Boston now, but I came home for this. I took time off work for a three-day weekend.

“I wouldn’t miss it. It’s Maine. It’s summer. It’s a beautiful day.”

Staff Writer Bob Keyes can be contacted at 791-6457 or at:

bkeyes@pressherald.com

Twitter: pphbkeyes