Susan Coolidge was the pen name of nineteenth-century American author Sarah Chauncey Woolsey. Born to wealth, Coolidge worked as a nurse during the Civil War before returning to her family home to take up a career in writing. Although best known for her classic Katy series of children s novels including What Katy Did and What Katy Did Next, Coolidge also published more than twenty works of fiction, and edited The Autobiography and Correspondence of Mrs. Delaney and The Diary and Letter of Frances Burney. Coolidge died in 1905.