williams married eliza (lily) biddle of detroit in 1879. she descended from the biddle family of philadelphia. her father was william s. biddle of grosse ile, michigan and she was granddaughter of john biddle, an early mayor of detroit and congressman. her mother was susan d. ogden and her maternal grandfather was judge elias b. d. ogden of the supreme court of new jersey. lily was sister to dr. andrew p. biddle, general john biddle, and first lieutenant william s. biddle, jr.