Boston Light, the last manned light house in the United States, is losing its keeper on New Year's Eve.

Sally Snowman, 72, became guardian of the historic lighthouse constructed in 1716, in 2002. She is its 70th keeper. "The first 69 were all men," she proudly told CBS News.

The heartwarming and heartbreaking history of Snowman's devotion to her position has been sweeping the nation, and also the world.

In a quick-changing society where technology is projected to replace many jobs across industries, the disappearance of one so rooted in our country's founding deserves pause.

Here is the story.

How Snowman became keeper

Snowman's father was a Coast Guard Auxiliarist, she told 9 News in Australia nearly a year ago, when the news of her forced retirement first came.

It was he who introduced her to the island in the summer of 1961, when he brought her along to meet other Auxiliarists in front of the lighthouse for a picnic.

"We anchored the boat, I stepped out, looked up at the lighthouse and said to my father; 'Daddy when I grow up, I want to get married out here,'" Snowman said to 9 News.

But it never occurred to Snowman that she would be hired to "man" the Light, she told Dorothy Wickenden of the The New Yorker. Snowman struggled in school. After barely passing, she gravitated towards caretaking jobs like childcare, elderly care and work with the disabled.

Still curious about her learning difficulties, she went on to obtain an online Ph.D. in neurolinguistics from Walden, "because I wanted to find out why my brain was so scrambled," Snowman said.

She learned she had dyslexia and attention-deficit disorder, and the sea? It brought her great comfort.

After learning some from her father, Snowman put in a request to work as the assistant keeper on Little Brewster, the island that holds Boston Light. She met her husband there, a civil engineer. Their experience on the island led them to write a book together on the history of Boston Light.

In 1994, the two married on the island just as she'd promised her father she would as a girl.

It was the publishing of the book that landed Snowman the job of keeper.

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The history of "the keeper"

Light house keepers, first called "wickies," began their work under the United States Lighthouse Service, founded in 1789.

The Service was the first Public Work Act of the first United States Congress, according to the National Park Service.

In 1896, lighthouse keepers became civil service employees until 1910 when Congress created the Bureau of Lighthouses. The U.S. Coast Guard oversaw the role starting 1939 until after 9/11 when civilians were hired to free up the Coast Guard during a time of war, according to the U.S. Department of Commerce Research Library.

By 1990, most lighthouses were automated, with one exception.

At Boston Light, Sally Snowman remained.

A final goodbye

Snowman was restricted to daytime maintenance trips after the lighthouse failed a safety inspection in 2018, CBS News reported.

In a recent video, Snowman shared that the lighthouse is being "taken over by another entity."

"It's called a stewardship transfer," she said. There will be a transfer of ownership through the National Historic Lighthouse Preservation Act of 2000.

"So, unfortunately, my job is coming to an end," said Snowman. "The keeper's position is going away."

Snowman will spend time at the Lifesaving Museum in Hull when her heart aches to be back at the lighthouse. "I know I'll miss it," she shared with CBS News.

Her hope is that she can keep working at Boston Light as a volunteer tour guide, Snowman shared with NPR.

As for parting words? Like the sign outside the keeper's house on the water's edge of Little Brewster, Snowman wants the world to know: “We will leave the light on for you.”