Born in Cambridgeport, Massachusetts, on May 23, 1810, Fuller received an intellectually rigorous classical education, whose boundaries she challenged when she won admittance to the male-only halls of Harvard's Library, where she continued her reading, research, and study of languages (she was especially fond of French and German Romantic literature, and was an able scholar of German, French, Italian, Greek, and Latin). After a period of teaching and attending to family concerns in Groton, Massachusetts, Fuller set about to carve for herself a niche in the Transcendentalist community. Invited by Emerson to visit him in Concord in 1836, it was not long until she had made captive to her conversation not only Emerson and his wife Lidian, and their circle, but also the Alcotts. Her introduction to Bronson Alcott proved fortuitous; the idealistic educator invited her to replace Elizabeth Peabody at his innovative Temple School in Boston, which Margaret did in December of that year.

After Alcott's experiment went bankrupt, Fuller organized a series of "Conversations" or seminars for women, which she offered in Boston from 1839 to 1844. So popular were the subscriptions to these discussions, and so spellbinding a conversationalist was Fuller, that she attracted not only the wives of prominent citizens, but also other sympathetic social reformers. Her method--one she shared with Bronson Alcott--was Socratic; each conversation was devoted to a philosophical question, and Margaret would engage the participants in discussion and dialogue before expounding her own views with a clarity of thought and luminosity of expression that dazzled her listeners. That women could have their own opinions on matters outside their "sphere" proved an intoxicating proposition. One of the lasting results of these Conversations was Fuller's publication of her 1845 feminist tract, Woman in the Nineteenth Century. It was also during this period that she and Emerson founded the Transcendentalist journal The Dial, in 1840. Fuller served as editor for the first two years, turning the publication over to Emerson's editorship in 1842.

After The Dial ceased publication in 1844, Fuller was invited by Horace Greeley, owner and editor of the New York Tribune, to relocate to that city and serve as literary and cultural critic for the paper. She did so, boarding for a time with Greeley and his wife, before taking her own lodgings. The period proved to be one of personal as well as intellectual growth in Fuller's life. Not only did she embark on what was likely her first romantic liaison--revealed only years after her death with the publication of her letters to the man, whose name was James Nathan--she also increased her awareness of urban poverty and strengthened her commitment to social justice and to the causes that concerned her: prison reform, Abolitionism, women's suffrage, and educational and political equality for minorities.

In 1846 Fuller embarked for Europe as a foreign correspondent for the Tribune. After touring England and France, she settled in Rome in 1847, where she entered the last vivid phase of her all-too-short life. Introduced to Giuseppe Mazzini, the leader of the Italian Unification Movement, she soon embraced the cause of Italian freedom. Her partisanship was also sparked by her falling in love with one of Mazzini's lieutenants, the Marchese Giovanni Ossoli, with whom she had a son out of wedlock and played an active role in the Siege of Rome in 1849. The hopes of the liberationists were dashed after the failure of their revolt, and Ossoli and Margaret married and decided to go to America with their son, Angelino. They set sail from Livorno on May 17, 1850, reaching the waters off Fire Island (New York) on July 19, where in the early hours of the morning the ship struck a sandbar and slowly sank. Fuller, Ossoli, and Angelino drowned.

Her shocked friends mourned her lavishly. Of the numerous tributes, the reminiscence by her fellow journalist Charles T. Congdon is one of the most touching:

"In American literature she will remain a remarkable biographic phenomenon, while the tragic death of this Lycidas of women, a most painful personal story of shipwreck, was intensified by so many melancholy incidents that whoever, long years hence, may read them, will wonder how the gods could have been so pitiless, and why the life of new happiness and larger intellectual achievement which was before her should so suddenly have ended upon that savage and inhospitable shore."

--Thomas Hampson and Carla Maria Verdino-Süllwold, PBS I Hear America Singing