For young Carrie Prudence Winter, the decision to work in Hawaii as a missionary school teacher, thousands of miles from her fiance, was both exciting and emotionally difficult.

Winter had agreed to a three-year position, which meant she would not see her beloved, Charles Kofoid, or return to Connecticut until 1893.

But she would tell him everything by using the most intimate medium of her era: the letter. Every steamship sailing from Hawaii carried her lengthy, lively descriptions of her life as a teacher, encounters with Hawaiian monarchy, the politics of annexation and even the flirtations of a local suitor.

And like most letters, they were never meant to be seen by anyone besides Winter’s fiance.

Until now. A new book, "An American Girl in the Hawaiian Islands: Letters of Carrie Prudence Winter 1890-1893," (University of Hawaii Press, $39), chronicles Winter’s time in Hawaii — and the Hawaii of the time — through the hundreds of handwritten letters she sent to Kofoid.

Authors Sandra Bonura and Deborah Day believe it’s something of a miracle they could even tell this story. For more than a century, the letters were hidden in a forgotten trunk in the attic of the Berkeley, Calif., home Winter and Kofoid shared after they were married.

Day found them in 2008 when the house was getting a new roof. As an archivist at the Scripps Institution of Oceanography, which Kofoid helped found, Day suspected that his old house might yield a hidden treasure.

Her hunch was rewarded when she climbed into the attic and found, hidden behind a support wall, five dust-covered trunks. Four of them contained research conducted by Kofoid, a respected 20th-century scientist, but the fifth contained Winter’s love letters, rare photographs of her life in Hawaii and essays from her students at the Kawaiahao Seminary for girls.

The book contains 300 letters that open a window into a 19th-century courtship.

"This was so private," said Bonura, a San Diego professor of education. "These are letters that she knew only one pair of eyes would ever see — her fiance. These are better than any diary or journal. These are private thoughts and observations, and that is beauty."

One of Winter’s frequent topics was the discipline she delivered onto her students. Typical of the period, that discipline often included beatings and locking the girls in closets, Bonura said.

Winter would tell Kofoid of her actions.

"She had to tell him," Bonura said. "It was as if he was her confessor. She would apologize for telling him something horrible. I think it was her catharsis. She needed to be absolved of this. He wrote her back and told her, ‘What are you doing? Quit hitting those girls.’"

As the book came together, some of those who saw it in draft form made requests the authors deemed unacceptable, according to Bonura. Some suggested she remove any hint of prejudice because it might hurt the feelings of the descendants of the person being quoted. Another person said to edit out any mushy love references, but these were love letters so that was impossible, Bonura said.

"I kept editing based on too many people," she said. "At the end of the day, I wanted to edit a book that I wanted to read. There is still some prejudice there but it is true to the time."

The authors gave something to Winter she could not achieve in life. The young schoolteacher saw herself as a writer and hoped someday to write a book about her time in Hawaii.

All she managed, though, was a magazine article in 1893 that ran under the headline "An American Girl in the Hawaiian Islands" — the same title of the edited book of her letters.