Mystic — Mubarak Mohamme of West Haven stood on a dock at Mystic Seaport Thursday morning with a huge smile on his face as his girlfriend, Djene Dumbouya, took his photo.

Mohamme was celebrating his 25th birthday Thursday, but that was not the reason he was smiling. Instead, it was the certificate he was proudly holding up in the photo.

Mohamme was one of 75 people from 33 nations who became U.S. citizens Thursday morning during a naturalization ceremony at Mystic Seaport that coincided with Flag Day.

“I feel so excited, words cannot express it. I’ve been waiting for this for so long,” said the native of Ghana.

Mohamme said he came to New York with his family when he was 11 and then moved to West Haven. A Comcast employee, he is attending Gateway Community College in New Haven working toward a degree in computer science.

He said that having been here for more than a decade, he wanted to take advantage of the privileges of being a citizen.

“As an American citizen, you have a passport to the whole world. You have such opportunity,” he said.

Natasha Dhupan, 25, of Newington, came here from Guyana eight years ago and recently graduated from Central Connecticut State University.

“This really means something. It means you are part of everything in this country,” she said.

Stephen White, president of the Seaport, said a museum employee suggested that the Seaport host a citizenship ceremony.

Because of its commitment to telling American stories in addition to presenting exhibits such as “Voyages: Stories of America and the Sea,” which tell the story of the country’s maritime heritage including immigration, White said it seemed a natural fit for the museum to host the ceremony.

“It’s our story as Americans and now it’s your story,” he told the new citizens.

All of the new citizens received copies of the book “Voyages” along with a yearlong membership to the Seaport.

White told the new citizens and their families that earlier generations of immigrants arrived by sea.

“It was difficult, but it was a voyage of hope and anticipation,” he said.

He said that when they left the ceremony, they will have completed one leg of their voyage and will be leaving on another.

Swearing in the citizens who recited the Oath of Allegiance was U.S. District Court Judge Janet C. Hall, who told them that the United States has served as a magnet of opportunity for generations of immigrants before them.

“It’s a wonderful day for you, your families and friends. It’s also a wonderful day for the United States of America because it now has the benefit of your talents and enthusiasm in building a better country for your children, their children and children to come.”

She said the new citizens enrich the United States by bringing the heritage and culture of their home countries, giving “our country its complexity and strength.”

Hall urged all the new citizens to go to their town halls Thursday and register to vote, not just in national elections but in local contests where she said they can have the most direct impact on their daily lives.

She urged them to share their ideas, serve their communities and support their school systems.

“I hope your choice of America will bring you lifelong happiness, and America will benefit from your choice of becoming a citizen,” she said.

j.wojtas@theday.com