Sarah Chauncey Woolsey was an American children's author who wrote under the pen name Susan Coolidge. Woolsey was born on January 29, 1835, into the wealthy, influential New England Dwight family, in Cleveland, Ohio. Her father was John Mumford Woolsey (1796-1870) and her mother Jane Andrews, and author and poet Gamel Woolsey was her niece. Her family moved to New Haven Connecticut in 1852. Woolsey worked as a nurse during the American Civil War (1861-1865), after which she started to write. She never married, and resided at her family home in Newport, Rhode Island, until her death. She edited The Autobiography and Correspondence of Mrs. Delaney (1879) and The Diary and Letters of Frances Burney (1880). She is best known for her classic children's novel What Katy Did (1872).