Eighteen cyclists and six drivers traversed the continental United States in 10 days, braving wind, fire, heat, and rain to raise awareness and funds to fight childhood cancer. A celebratory swim near Squantum Point in Quincy Tuesday marked the end of their 3,600-mile trek and a completion of their goals.

For at least one rider, the goals were personal.

Riley Adams, 18, rode for his sister, Eden, who died from neuroblastoma in 2008 at 8 years old. Months before her death, Adams and his family were in Washington, D.C., helping raise funds for a cure, when he first encountered Team Will.

Named for William Kiefer, a 2-year-old who died five months after doctors diagnosed him with cancer, the bicycling group rides across the country, visiting children hospitalized with cancer and raising funds for cancer research.

“We just created a route and decided to ride,” said Ken Scarberry, a close family friend to the Kiefers who created Team Will with two friends at a Sacramento coffee shop.

“Our goal was to visit hospitals, talk to people, encourage people, and give them hope . . . and help raise awareness that childhood cancer kills more kids than any other disease.”

The 2012 transcontinental ride was the fourth for the team.

It was during the team’s second trip that ­Adams and his sisters crossed paths with the ­cyclists in the nation’s capital. Both Eden and ­Adams’s stepsister Hannah, who also battled cancer but is now in remission, signed riders’ jerseys.

In 2009, Adams began cycling. In 2010, he came across Team Will on Facebook and decided to join its ranks.

“I think this is a very good way of helping the kids and their families take their minds off everything, even if just for a few moments,” he said.

During this year’s 10-day journey, the team conquered the Rocky Mountains, braved rampant wildfires in Colorado, overcame head-winds in the Midwest, and suffered through several days with temperatures higher than 110 degrees, Scarberry said.

Adams and the rest of the 2012 team were met in Quincy by more than 30 family members and friends who flew from California to celebrate the ride’s end.

“I’m really proud he made it across,” Adams’ sister Hannah, 11, said. “I missed him a lot.”

The team raised more than $115,000 for childhood cancer research and visited 18 hospitals and several community events along the way.

“We know that we can’t cure them,” Scarberry said, “but if we can just . . . change their thoughts so they don’t have to think about what’s going on right now — that’s what we try to do.”

Three teams of riders divided the journey into eight-hour segments each day, so a rider was physically on the road 24 hours a day. On average, riders covered 70 to 120 miles each per day, with about four hours of sleep per night.

“Really what pushes us through is our heroes and all these kids we meet throughout the ride,” said Adams, who ­received 16 autographs on his jersey. “It’s amazing to see their strength and the look on their faces when we ask for their auto­graphs.”

Each rider trains for at least one year in riding, communicating with children and families in the hospitals, and fund-raising, before joining one of the coast-to-coast rides. On those rides, team members carry pictures of children fighting cancer as a reminder of their purpose.

“This is not about the ride,” Scarberry said.

Shortly after dipping his front tire in the Atlantic Ocean and taking a victory swim to ­officially finish the trip, Ricky Ng, 24, pulled out a letter he wrote to his heroes Isaac and Madison, children who have cancer and whose photos he carried with him on the ride.

“I’m going to send this picture to them, show them a little bit of Boston and that I’m thinking about them,” Ng said, as he snapped a shot of the letter with the city skyline as a backdrop. “They really did help me along on this ride and really did inspire me.”