When William Dabney Smithson Jr. was born on 10 September 1832, in Clark, Kentucky, United States, his father, William Dabney Smithson, was 30 and his mother, Eliza Jane Edmonson, was 23. He married Mary Ann Fuqua on 27 February 1862, in Vernalis, San Joaquin, California, United States. They were the parents of at least 4 sons and 3 daughters. He lived in Southwark, Surrey, England, United Kingdom in 1833 and Scott, Illinois, United States in 1850. He died on 3 November 1897, in Acampo, San Joaquin, California, United States, at the age of 65, and was buried in Liberty Cemetery, Acampo, San Joaquin, California, United States.