Helen Archibald Clarke was born in Philadelphia, Pennsylvania, to a musical family. Her father Hugh A. Clarke was professor of music at the University of Pennsylvania, and she attended Penn as a special student for two years, before women were formally admitted. She met Charlotte Endymion Porter, who would become her lifelong partner, when Porter accepted her article on music in Shakespeare for Shakespeariana, a journal she edited. In 1889, Clarke and Porter launched a new monthly magazine, Poet Lore, devoted to Shakespeare, Browning, and comparative literature. Much of the content was written by the two editors. Poet Lore found an immediate and growing audience among the literary clubs and societies proliferating in 19th-century USA. Two years later, they moved the magazine to Boston; and by 1896, it had become a quarterly. Over the years, Poet Lore introduced American readers to the works in translation of European writers such as Henrik Ibsen, August Strindberg, Gabriele D’Annunzio, Selma Lagerlöf, Maxim Gorky, Maurice Maeterlinck, Rabindranath Tagore, and other moderns. Clarke and Porter published a collection of short stories they had translated called Clever Tales (1897); a 12-volume complete edition of Browning’s works in 1898; a 6-volume edition of Elizabeth Barrett Browning’s works in 1900; and the 12-volume Pembroke edition of Shakespeare in 1912. Clarke adapted Browning’s Pippa Passes into a play that was staged in Boston in 1899. In 1903 they sold Poet Lore, which they continued to edit, in order to work on other projects. Clarke published Browning’s Italy (1907), Browning's England (1908), A Child's Guide to Mythology (1908), Longfellow's Country (1909), Hawthorne's Country (1910), The Poets' New England (1911), and Browning and His Century (1912), along with a number of musical pieces for children. She and Porter co-founded the American Music Society.