Harriet Martineau was born in Norwich, the daughter of Thomas Martineau, a Unitarian importer of wine and manufacturer of silks and woollens, and his wife Elizabeth. Unusually, the young Harriet studied Latin, French, composition and arithmetic with her brothers. Incipient deafness led her to bury herself in literature, and she began to write. When her brother James left for college in 1822, she overcame her sense of loss by writing for publication, contributing religious and philosophical essays to the Monthly Repository. Following the collapse of the family business in 1829, Harriet had to write for a living and she quickly found a publisher for a series of stories popularising the new subject of political economy. Her Illustrations of Political Economy (1832-34) caused a sensation, and she became a public figure.
Harriet Martineau quickly established a wide circle of friends including Charles and Erasmus Darwin, Thomas Carlyle, Fanny Wedgwood, Charlotte Brontë, George Eliot, Charles Dickens, William Wordsworth, and Florence Nightingale. With this wide circle she kept up a lively correspondence as she retired due to ill health, first to Tyneside and then to Ambleside where she built The Knoll. Harriet was, however, given to quarrelling with literary luminaries, Thomas Carlyle mordantly commenting that she was 'a too noisy distinguished female victorious mainly by her smallness; and who not only waves banners in her own triumph, but insists on your waving banners too'.
Nonetheless Harriet Martineau remained influential, her knowledge of America leading her to be appointed as American correspondent to the Daily News, where her anti-slavery and pro-neutrality views were important during the Civil War. She also continued to publish more substantial works such as Letters on the Laws of Man‘s Nature and Development and The Positive Philosophy of Auguste Comte, as well as her Guide to the Lakes, and worked to improve the conditions of the poor, writing and lecturing on sanitation. Although increasingly an invalid, Harriet Martineau continued to write until 1873, eventually dying in 1876.