Susan Coolidge was the pen name of Sarah Chauncey Woolsey, an American author best remembered for her classic children’s novels. She was born on January 29, 1835, in Cleveland, Ohio, into a prominent New England family and later moved with her family to New Haven, Connecticut. During the American Civil War, Woolsey served as a nurse, an experience that preceded her literary career. She eventually settled in Newport, Rhode Island, where she lived for much of her later life and devoted herself to writing and literary work.

Coolidge achieved lasting fame with the publication of What Katy Did in 1872. The novel follows the lively and strong-willed Katy Carr as she grows from an impulsive girl into a thoughtful young woman, and the Carr family was inspired in part by Woolsey and her own siblings. The book proved popular enough to become the beginning of a series that continued with What Katy Did at School, What Katy Did Next, Clover, and In the High Valley. Coolidge also wrote numerous other books for young readers, including Eyebright, A Little Country Girl, Nine Little Goslings, and collections of stories, poems, and ballads.

In addition to her fiction, Coolidge wrote poetry and contributed stories and verse to popular nineteenth-century magazines such as St. Nicholas, The Atlantic Monthly, and Scribner’s Magazine. She also worked as an editor, preparing collections of the writings of figures including Frances Burney and Mary Delany. Coolidge never married and continued writing throughout her life, dying in Newport on April 9, 1905, at the age of seventy. Her Katy books in particular have remained enduring examples of nineteenth-century children’s literature, introducing generations of readers to stories of family life, personal growth, friendship, and resilience.