Despite her best intentions, quick-tempered Katy Carr's efforts to be tidy and good-tempered always seem to land her in trouble. Then, one terrible day, Katy has an accident, but it is still a long, eventful time before she learns to be as loving and as patient as her beautiful invalid cousin Helen.
Susan Coolidge was the pen name for Sarah Chauncey Woolsey who was born in 1835 into a wealthy and influential family in Ohio, USA. She spent much of her childhood in Connecticut after her family moved there in 1852 and worked as a nurse during the American Civil War, after which she started to write. She never married, and resided at her family home in Rhode Island until her death in 1905.
The fictional Carr family, who feature in What Katy Did, are based on her own family, with Katy Carr inspired by Woolsey herself and the brothers and sisters by her four younger siblings.