Will Cushing had four siblings (and six half-siblings from his father’s first marriage): elder brothers Milton, Howard and Alonzo, and younger sister Mary Isabelle. The bonds of affection among them were strong. “One trait, was very remarkable in our family,” observed Mary Isabelle . “That was the respect and courtesy manifested toward each other. I never received a reproof or heard an impatient word.” After Will’s father died, his mother’s family, particularly Congressman Francis Edwards and Commodore Joseph Smith, helped guide his development. In 1870, Will married Katherine Forbes, the daughter of a Fredonia NY merchant. They had two daughters.