Katherine Vaz. (Photo: Beowulf Sheehan)

From being the first Portuguese-America to having work recorded for the archives of the Library of Congress to being named by the Portuguese American Leadership Council of the United States as among its all-time most influential women, Katherine Vaz has led an inspirational career, especially to Portuguese Americans. Vaz continues to create the stories she never saw as a child; her newest book, “Above the Salt,” focuses on the story of two Portuguese refugees, which she speaks about Thursday at Porter Square books. Though Vaz is a New York resident, she’s had fellowships at Harvard and Radcliffe and her writings will find many native speakers in Cambridge and Somerville; the cities have been a center for the Portuguese since soon after the Civil War. We interviewed her Jan. 5; her words have been edited for length and clarity.

What inspired “Above the Salt”?

It was a labor of love that started when I was giving a talk at the Library of Congress in the Hispanic Division about some of my previous work. My friend, Ieda Siqueira Wiarda, was there, and she told me, “We’ve got this unusual exhibit in the map room at the Library of Congress, do you want to see it?” It was something called the Portuguese Protestants of Illinois. I thought, “Well, that’s pretty funny and interesting.” I had never heard of this story – now I know everything about it. “Above the Salt” is based on the true story of a group of people on the Portuguese island of Madeira who were converted to Presbyterianism. There was a lot of religious violence and upheaval. They fled to Springfield and Jacksonville, Illinois, at the time of Lincoln. After doing a bit of research, I came across a story of a man named John Alves who had been raised in jail as a baby with his mother, who had been condemned to die for heresy. He grew up, met and courted a woman, Mary, who he met at the Lincoln household, went off to fight in the Union army and lost track of her. And in an interview that I found, which he gave as an old man, he spoke about how he went back to the Lincoln household and he was so overcome by thoughts of Mary that his hand trembled so much that he couldn’t sign the guestbook, the Lincoln ledger. The fact that his hand trembled so much even as an old man remembering her was a quality of emotion that kept me going for the years and years and years it took to write this book. He also didn’t say in the interview what happened to the woman named Mary that he fell in love with. To me, that blank space was where the novel grew.

Why is Portuguese representation important to you?

My father was from the Azores, and he and his family came to California. My father once said to me, there are poets in our community, there are essayists and historians, but not many people are doing fictional short stories and that kind of thing. My dad did write a historical book called “The Portuguese in California,” and I was encouraged when I was growing up to write and to be in the arts. I was very lucky to have parents who were willing to have their children follow whatever path was their destiny or their desire. I’m kind of steeped in Portuguese culture. I grew up around a lot of cousins and they were Azorean, and they were always great storytellers. When I was in college, I wrote a story and a teacher said to me, “You tell me such amazing, crazy, wonderful stories about your family and what you know about the Portuguese culture in America – Why don’t you write a story about that instead of trying to write what everyone else is writing?” And so I wrote two stories and I sent them into the National Endowment for the Arts, and I got a fellowship. That kind of set the course for me: I found my voice and I found my material.

Apart from the clearly Portuguese characters, how did Portugal and your heritage there influence your work?

My second novel was about a Portuguese nun who wrote love letters while she was in a convent. And while there is a certain belief that she was invented by a Frenchman who wrote love letters and attributed them to a nun, a lot of people in Portugal and elsewhere believe that she was a real person. I wrote a novel about her that got a lot of coverage in Portugal. That had basically nothing to do with America at all. One of the great heroes I have there, a woman named Maria Teresa Horta – one of the three Marias who got in trouble during the dictatorship for what she had written about women and freedom – interviewed me and she called me “Our American cousin.” That is, I think, the perfect wonderful description of my relationship with Portugal – I’m the American cousin.

What do you hope readers take away from “Above the Salt”?

I hope they take away an eye-opening look at a segment of the population that is vital and important, and is less well-known. I don’t think many people know that there was an enormous group of people from Portugal who were adopted in Illinois. It’s to help people see an immigrant culture. I want people to understand that at the time, these migrants were penniless refugees, and land and homes were found for them in Illinois. There was an enormous sense of generosity that America practiced regarding these people.

And do you have any favorite lines from “Above the Salt”?

“Sometimes she feels as breakable as a teacup, or a fragile plate that is kept in a cupboard after all the other plates in the set got broken long ago. Her father vows to protect her and he tucks her into her feather bed while wishing her pink dreams, the Lusitanian way of granting sweet dreams, night rest in the shade of peonies, the raptures of sunrise, and the tint of the camellias that got the best of God’s paintbrush. Sail into pink and seize it as yours, my living angel, my own dream incarnate.”

• Katherine Vaz speaks at 7 p.m Thursday at Porter Square Books, 25 White St., Porter Square, Cambridge. RSVP here.