1880 U.S. Census (Ancestry.com): Persy Foster (33 b. England) living in Elmira, Salano Co., CA with wife, Amy (33 b. VA) and 4 kids: Maggie (13 b. Kansas); Charles (12 b. Kansas); Lillie (3 b. CA); and Gracie (2 b. CA).
1900 U.S. Census (Ancestry.com): Percy Foster (b. Nov 1847 England); married 26 yrs, living in San Jose, Santa Clara Co., CA with wife, Annie (Jan 1847 VA) and 3 kids: Gracie (b. Jun 1877 CA); Geo H. (b. Oct 1881 CA); and Fletcher (b. Jan 1890 CA).