Annie Adams was born in Boston, Massachusetts. At the age of twenty, she married book publisher James T. Fields. James' company, Ticknor & Fields, occupied a building where books were printed in the attic and sold through a shop on the ground floor. The building was the former site of the seventeenth century home of Anne Hutchinson, an early feminist expelled by the male leaders of the Massachusetts Bay Colony because of her progressive ideas about the role of women in the Church and society.

Annie's marriage to Fields was unusual in many respects. At a time when the purpose of most marriages was to secure heirs and a housekeeper, with love in the modern sense rarely entering the equation, theirs was based on genuine love, affection, and mutual respect, and remained childless, possibly by choice. When James became editor of the Atlantic Monthly in 1861, Annie advised him on which pieces to accept for publication, as she also advised him on which new authors' books to publish.

Annie Adams-Fields became a major figure in the cultural and social circles of Boston, hosting many parties whose guests the most notable figures in both Boston and American society, and holding lectures and readings in her library whose speakers included Charles Dickens, Nathaniel Hawthorne, Ralph Waldo Emerson, Henry W. Longfellow, and the Reverend Henry Ward Beecher, whose sister, Harriet Beecher Stowe, was the author of Uncle Tom's Cabin and also a close friend of Annie.

She also assisted Harriet Stowe in her literary research, and helped along the budding careers of Rebecca Harding Davis, and Willa Cather. One writer in particular whom Annie helped, Sarah Orne Jewett, would in time become first a close friend and then a lover. In addition to her cultural activities, Annie was the founder of many charities for Boston's poor, and also devoted her time to the abolitionist movement and campaigns to win women the right to vote and be admitted to medical schools. The New England Women's Club was one of many organizations which she founded. How to Help the Poor was a guide for charities which she wrote.

When James Fields died in 1881, Annie turned for solace to Sarah Orne Jewett, and the two women lived together for the next 28 years (from 1881 to 1909). Once, when visiting a spiritualist, Jewett was told that the spirits of her father and James Fields not only approved of her relationship with Annie, but that they had actually orchestrated it. Theirs became a relationship so close and so devoted that it was in fact a marriage in all but name. In fact, devoted cohabital relationships of this kind between widows and "spinsters" were so common in nineteenth century Boston that the term "Boston marriage" was coined for them, even when such relationships were known in other cities.

Annie's own sister, the painter Lissie Adams, lived in a similar relationship with a woman in Baltimore. Indeed, many of Jewett's and Fields' female friends, including Violet Paget, Alice James, Charlotte Cushman, and Alice French, aka Octave Thanet, lived in such arrangements with other women. While not all these relationships contained amorous or sexual elements, the term "Boston marriage" quickly became a euphemism for lesbianism.

During her time with Sarah Orne Jewett, Annie Adams-Fields, who had spent her early years nurturing and promoting the works of so many other female writers, became herself a prolific and accomplished author, producing Under the Olive (1880), a book of verses; James T. Fields: Biographical Notes and Personal Sketches (1882); Authors and Friends (1896); The Life and Letters of Harriet Beecher Stowe (1897); and two plays, The Return of Persephone and Orpheus (1900). She also continued her work on behalf of charity and the suffragist movement.

For the rest of her life following James Fields' death, Annie wore black or purple, the traditional colors of mourning, and often wore a mourning veil. She was equally dedicated in her expressions of grief and heartache following Sarah Jewett's death in 1909. While Jewett's publishers tried to suppress the love letters exchanged between herself and Annie Fields, enough of such letters survived in Annie's own personal collection to leave little doubt as to the nature of their relationship.

In 1998 the relationship between Annie Adams-Fields and Sarah Orne Jewett was one of many episodes of GLBT history featured in the documentary film, Out of the Past, which itself centered around the efforts of Salt Lake City student Kelli Peterson to start a GLBT student organization at her high school. More recently, a biography of Annie Adams-Fields by Rita K. Gollin has appeared, finally given her more coverage then the odd mention she has usually received in encyclopedic entries for her husband. Nearly ninety years after her passing, Annie Adams-Fields is finally beginning to be recognized as a significant figure in social and literary history.