The original 1953 paperback.

When The Price of Salt was first published in paperback in 1953, Patricia Highsmith was flooded with thousands of letters from readers. The letters came addressed to the author “Claire Morgan,” the pseudonym Highsmith had used for the book, for fear of being labelled what she later called a “lesbian-book writer.” They arrived in the hundreds from male and female readers alike, thanking Highsmith for writing a book that finally showed a same-sex relationship that didn’t end in tragedy.

“Many of the letters that came to me carried such messages as ‘Yours is the first book like this with a happy ending!’” Highsmith wrote years later in a postscript. Other letters asked her for guidance: “I am eighteen and I live in a small town. I feel lonely because I can’t talk to anyone…”

The Price of Salt was a landmark book for queer America, offering readers a powerful and hopeful ending, one that didn’t see the two women at the center of the story end their affair, commit suicide, or attempt murder. But for most of its existence, the novel—which has been adapted into Carol, a new film by Todd Haynes—was overlooked by critics and left out of the canon of twentieth-century queer novels. Highsmith’s publishers rejected it. It eventually found success in a dime-store paperback version, brandished with the catchline “The novel of a love society forbids.”

Highsmith did not set out to write a groundbreaking work of lesbian culture. In the brief and unsentimental afterword she contributed to the novel’s 1989 re-issue, published as Carol, it’s clear she wanted to place more emphasis on the book’s craft than its queer content. She was inspired to write the book while working in the toy section of a New York department store, a time when she was “vaguely depressed and also short of money.” One morning, a tall blond woman entered her section and, after choosing a doll that Highsmith showed her for a Christmas present, signed a delivery docket and paid, asking that the doll be delivered to her house.

The hardcover first edition, published in 1952.

Highsmith decided to augment this fleeting, and mostly unremarkable, encounter into a story of a young woman’s romance with an older housewife, amplifying the emotional intensity she felt for this beautiful stranger into a novel of forbidden romance. After a bout of adult chicken pox, Highsmith feverishly plotted the story of The Price of Salt, mapping a cross-country road trip between the two women as their intense attraction is realized in highway hotel rooms and long car drives on deserted back roads.