In line at the John F. Kennedy Presidential Library and Museum, John W. Bates held a box of tributes to the 35th president: packets of commemorative coins, envelopes emblazoned with his image, and mementos from months after Kennedy’s assassination.

To his keepsakes, the Melrose resident had added several stamps — issued for the first time at the library Monday — to commemorate Presidents’ Day and the centennial of Kennedy’s birth.

“He just inspired people to do things you wouldn’t think about, to go places you don’t want to go, and to help people you hadn’t thought about,’’ said Bates. “The world would be a very different place if he had lived.’’

In a season marked by a political confusion, division, and unease, the Kennedy event placed the presidency under a lens of nostalgia and reflection.

Participants recalled Kennedy’s famous odes to unity, public service, and political participation as Postmaster General Megan Brennan unveiled the new stamp design. The black-and-white image of Kennedy on the stamp is from a campaign appearance in 1960.

Representative Joseph Kennedy III said the US Postal Service had chosen an image that showed President Kennedy’s confidence.

“His shoulders strong, his face lifted, his eyes looking up . . . ever hopeful, ever faithful that a country that was built on a truth that is as old as the Scriptures and as clear as our Constitution could shatter any horizon, shoulder any heartache, and survive any fall,’’ said Kennedy, a Newton Democrat.

“In the days and weeks and months ahead, may each of us hold tightly to that truth,’’ added Kennedy, whose grandfather, former US attorney general Robert F. Kennedy, was the president’s brother.

Hundreds gathered at the Dorchester museum for the release of the stamp, including the man who photographed its image. Ted Spiegel said he shot the picture while on assignment for the state of Washington in Seattle.

After the unveiling, Spiegel showed a series of images from that same Kennedy campaign stop, including one picture in which the candidate was greeted by an enthusiastic crowd. The picture on the stamp came later, he said, and to him it displays Kennedy’s will to lead.

“It feels good to be part of the carrying forward of the Kennedy legacy,’’ he said.

The 100th anniversary of Kennedy’s birth is May 29.

There were few direct references to President Trump at the event. Some of the speakers hinted at the differences in philosophies between Kennedy, a Democrat, and the current president.

US Senator Ed Markey, also a Democrat, said Kennedy’s commitment to social justice has influenced causes including the Black Lives Matter movement and several protest efforts that have emerged to challenge Trump.

The victory of the Irish Catholic Kennedy “was a message to all minority groups in America that they, too, could make contributions in civic life and participate in the noble calling of public service,’’ he added.

In another room of the presidential library, families brought their children to mark Presidents’ Day by writing letters to Trump. Ella Cheney, 9, of Dorchester, was trying to figure out what to tell the president.

She congratulated him on his new job and sent along her best wishes: “I hope you will make America great again,’’ she said aloud.

Her mother, Siobhan Cheney, laughed.

“Hopefully!’’ she said. “He’ll like that.’’

Across the table, 6-year-old Francie Ames of Brookline was working on a letter of her own.

“Why do you want to build a wall?’’ she asked. She told Trump that she cares about that cause because “it is mean.’’

Her brother, 11-year-old Henry, was writing a longer letter imploring the president to treat immigrants with compassion.

“If he actually reads it, I think he’d understand a little bit more about why people should be allowed in the United States,’’ he said.

Their mother, Wendy Ames, said her son’s and daughter’s comments were evidence that politics and the presidency matter to everyone.

“Talk or rhetoric around immigration makes them uncomfortable,’’ she said, “and they ask questions about it.’’

Andy Rosen can be reached at andrew.rosen@globe.com. Follow him on Twitter at @andyrosen.