Washington was the daughter of Carrie Butler, who was 15 or 16 when her daughter was born, and Strom Thurmond, then 22. Carrie Butler worked as a domestic servant for Thurmond's parents. She sent her daughter from South Carolina to her older sister Mary and her husband John Henry Washington to be raised in Coatesville, Pennsylvania. The girl was named Essie after another of Carrie's sisters, who fostered her briefly as an infant. Essie Mae grew up with her cousin, seven years older than she, who she believed was her half-brother. Washington was unaware of the identity of her biological parents until 1941, when she was 16. Her mother told her the full story then and took her to meet Thurmond in person.