Hello Alan,
I think this may be the son theat was born in England 1878
1910 Census Chicago Ward 27, Cook, Illinois
Herbert S Foster 32 Born England. Immigrated 1892, NA. Married for 5 years. Plumber.
Harriett Foster 29 Born Illinois. Had 1 child and 1 survives.
George Foster 2 Born Illinois
Minnie Zierbogel 25 Servant.