1857 Birth:1637,2842 Birth year of 1857 calculated based on age of 3 years in 1860 census enumeration. Birth place of Moulton Township, Auglaize County, Ohio assumed because of family residence in that location in both the 1850 and 1860 enumerations.

1860 U.S. Census:2842 William Sillin enumerated in the household of his father John P. Sillin in Moulton Township, Auglaize County, Ohio, as a male, age 3, born in Ohio. Others enumerated in the household were his mother Hanna Sillin, a female, age 51, born in Virginia, and siblings Sylvanus, age 27; Amanda Jane, age 25; Sarah A., age 23; Elizabeth, age 22; Luther, age 19; Philip B., age 17; Malinda, age 13; and Louisa, age 8.

1870 U.S. Census:2843 William S. Sillin enumerated in the household of his father John P. Sillin in Moulton Township, Auglaize County, California as a white male, age 14, born in Ohio. Also residing in the household were siblings Amanda J., 36; and Louisa, age 19. James Richardson, age 17, was also enumerated as a farm hand.