In 1880, on the first anniversary of her marriage, author Sarah Orne Jewett penned a romantic poem to her partner. “Do you remember, darling, a year ago today, when we gave ourselves to each other?” she wrote. “We will not take back the promises we made a year ago.”

Jewett wasn’t addressing her husband—she was writing to her future wife, Annie Adams Fields. Over a century before same-sex marriage became the law of the land, Jewett and Adams lived together in a “Boston marriage,” a committed partnership between women.

They weren’t the only ones: For several years near the turn of the 20th century, same-sex marriage was relatively common and even socially acceptable. These women shared kisses, hugs and their lives—but today, few remember these pioneers of same-sex relationships.

Though homosexuality was taboo during the 19th century, intense and romantic friendships among women were common. At the time, women were encouraged to exist in a sphere separate from that of men. Public life, work and earning money were seen as the purview of men.

This ideology isolated women from the outside world, but it also brought them into close contact with one another. As women were viewed as devoted, asexual and gentle, it was acceptable for them to do things like kiss, hold hands or link arms, and openly express their affection for one another. At newly founded women’s colleges, for example, students gave one another bouquets of flowers, love poems and trinkets and openly declared their love. Having a crush on another woman wasn’t blinked at—it was expected and considered part of women’s college culture.

A group of New England women took this concept one step further by “getting married.” Though they didn’t commit to one another legally, they combined households, lived together and supported one another for the long term. These independent women pushed the boundaries of what society deemed acceptable for women by attending college, finding careers and living outside their parents’ home. But since they did so with other women, their activities were deemed socially acceptable.

In 1885, novelist Henry James explored the phenomenon in his book The Bostonians. The novel, which pokes fun at independent women, features a relationship between Verena Tarrant, an outspoken feminist, and Olive Chancellor, who becomes fascinated with the fiery speaker. They form a partnership and move in with one another, but when Verena decides to marry Olive’s cousin the relationship falls apart. The popular novel is thought to have contributed to the use of the term “Boston marriage,” though James never used the phrase in his book.

Boston marriages offered equality, support and independence to wealthy women who were determined to push outside of the domestic sphere. They also offered romantic love: Though each relationship was different, women often referred to one another as husband or wife, kissed and hugged, wrote passionate letters when they were apart and shared beds. However, this was not necessarily seen as sexual in the 19th century since women were assumed not to have the physical desires of men.

For some women, Boston marriages were used as a front for relationships that would be categorized as lesbian in the 21st century. As historian Stephanie Coontz tells NPR, “a pair of women who actually had a sexual relationship could easily manage to be together without arousing suspicion that it was anything more than feminine affection.” But for others, sex didn’t appear to be part of the equation. Rather, Boston marriages offered something even more appealing—independence.

Ironically, the practice faded as people became aware of lesbianism. At the turn of the century, the concept of “sexual inversion” made it possible to categorize relationships that had once been considered socially acceptable as sexually deviant.

Though Jewett and Fields lived together for over two decades, Jewett’s publishers seem to have edited out telling details from her letters to Fields, a society chronicler, to prevent readers from assuming they were lesbians.

It would take 100 more years for same-sex marriage to be legally accepted in the United States. But even in death, the commitment and love of same-sex partners from the 19th century lives on, like that of American novelist Willa Cather and her longtime companion, Edith Lewis. The pair lived together as committed partners for almost 40 years. They're now buried together in a New Hampshire cemetery.