AMHERST — Until taking the oath of U.S. citizenship Tuesday morning, Tashi Dhondup of Amherst had been without a country since 1959, when he left Tibet during the Tibetan uprising and took refuge in Nepal.

Eleven years after coming to the United States, Dhondup, accompanied by his daughters Chime and Tenzin, became an American citizen.

“I’m really happy,” Dhondup said, holding an American flag, as he received congratulations outside the Munson Memorial Library following a naturalization oath ceremony. “This is a very proud and happy moment, to become a citizen.”

Dhondup wasn’t alone.

Pushparanee Shanthalingam, an Amherst resident for 5½ years and originally from Colombo, Sri Lanka, also earned citizenship. The honor is the culmination of three months of study for her citizenship exam, during which she got help from her daughter, Sudarvili Shanthalingam, a research fellow at the University of Massachusetts, and assistance from the English as a Second Language program at Jones Library, which sponsored the ceremony.

“I am so happy to be a citizen,” Shanthalingam said

A retired psychiatric counselor, “Pushpa,” as she is known, had already been celebrating with neighbors and colleagues and has made many friends since coming to town, with her daughter observing that “people enjoy talking to her.”

Dhondup and Shanthalingam were among 49 Massachusetts residents, hailing from more than two dozen countries, participating in the ceremony, presided over by U.S. District Court Judge Katherine A. Robertson. “This is the most meaningful and joyful part of my job,” Robertson said.

“This country wouldn’t be what it is without people like you, who’ve chosen to live here, to raise your families here,” Robertson said.

“How incredible, how hopeful it is, that we’re welcoming citizens from 29 countries,” said state Sen. Jo Comerford, D-Northampton, as she spoke to the new citizens and their families filling the auditorium, with several people holding their young children in their arms and laps and several strollers lining the entranceway. “Your extreme amount of dedicated work is an inspiration.”

The ceremony recognized the ESL program and its citizenship services under coordinator Lynne Weintraub.

Weintraub, who said she provided some assistance to Shanthalingam, noted that the event came on both Constitution Day and National Citizenship Day. “Happy Citizenship Day, and congratulations,” Weintraub said.

Lynn Griesemer, president of the Amherst Town Council, thanked both the Jones Library and Center for New Americans, and expressed appreciation for the rich tapestry of diversity and culture the new citizens bring to the state and region.

Koby Gardner-Levine, district representative for U.S. Rep. Jim McGovern, asked those gathered to participate in government and the community, schools and libraries. “Being a citizen is not just a title, it’s an ongoing act,” Gardner-Levine said

He said they should aim to pursue justice, equality and peace and make lives better for others, and that the United States wouldn’t be the same without contributions of immigrants.

“This is such an uplifting and momentous occasion,” Gardner-Levine said.

“Let us learn from you and continue to be inspired by you, and grow,” said Lily Stowe-Alekman, staff director for state Rep. Mindy Domb, D-Amherst.

The ceremony began with a performance of the national anthem by Richmond Ampiah-Bonney and Robertson led the new citizens in a Pledge of Allegiance.

In addition to Sri Lanka and Nepal, other countries represented by the new citizens include Albania, Brazil, Cambodia, China, Colombia, Costa Rica, Côte d’Ivoire, Dominican Republic, Germany, Ghana, Guyana, India, Iraq, Jamaica, Kenya, Kosovo, Mauritius, Moldova, Philippines, Poland, Russia, Rwanda, Singapore, Slovenia, Ukraine, Uruguay and Vietnam.

All applicants had to submit a 14-page application, pay an application fee set at $760, go through an FBI criminal records check, and appear for a personal background interview, in English at the U.S. Citizenship and Immigration Services office. If an examiner determines that the student can speak, read and write English, knows the fundamentals of U.S. history and government, and meets the legal qualifications for citizenship, the student is scheduled for an oath ceremony.

Following the event, representatives of the League of Women Voters of Amherst were on hand to register people to vote, which they are eligible to do immediately and can vote in the presidential election, either in November or via early voting.

“It’s important to realize the right to vote is a right of theirs,” said Andrea Battle, a member of the League’s steering committee.

For Kelly Appel of Southborough, accompanied by her husband, Marc, and, their son Benjamin, 3, it was worth making the 90-minute drive from their home to be part of the ceremony.

Originally from Singapore, Appel came to the United States on a student visa and has been in the country for 16 years. She was sponsored by her workplace to achieve citizenship.

“It felt like the right time to become a citizen,” Appel said. “It was seamless and was much easier than I expected.”

Posing for photos with her family and waving the American flag, Appel said it would be a memorable day.

“I’ve felt so supported and am amazed at how welcoming everyone is,” Appel said.