Hi.I'm not related to this family.I noticed mother & son living in Santa Rosa in 1880, with Sarah J. Mead listed as married.There is a Sonoma,California Voter Registration list with 3 Meads born in Penn and living in Santa Rosa in 1879.They were:
Wilson Henry Mead, b. 1841 Penn, Policeman - He married Emma H. Whitlock, so he can't be yours.
Willard Rylan Mead, b. 1848 Penn, Teamster - He married Samantha VanWinkle so he can't be yours.
William Edward Mead, b. 1841 Penn, Carpenter - This IS a possible father for your Walter J. Mead.He is listed in the Sonoma directory up to the year 1888.
I can't find him in the 1880 or 1870 Census.Here he is in the 1860 Census:
1860 United States Federal Census about Wm Edward Mead Name: Wm Edward Mead Age in 1860: 18 Birth Year: abt 1842 Birthplace: Pennsylvania Home in 1860: Santa Rosa, Sonoma, California Gender: Male Post Office: Santa Rosa Household Members: Name Age Wm Mead 43b. 1817 Penn; farmer Catherine Mead 39b. 1821 Penn Wilson H Mead 20b. 1840 Penn Wm Edward Mead 18b. 1842 Penn ** Sarah Ellen Mead 16 b. 1844 OH Willard Ryland Mead 12b. 1848 Penn
Interesting!He is the brother (presumably) of the other two Meads listed above.I found one tree on Ancestry.com that has him married to Sarah J. Curry on 3 Jul 1872 in Santa Rosa.They also have a death for him on 30 Jun 1924 in Sonoma, buried in the Santa Rosa Rural Cemetery.This may be a very good lead for you.
Here is Sarah J. Curry in 1870:
1870 United States Federal Census about Sarah J Curry Name: Sarah J Curry Age in 1870: 18 Birth Year: abt 1852 Birthplace: Indiana Home in 1870: Analy, Sonoma, California Race: White Gender: Female Post Office: Sebastopol Household Members: Name Age Joseph H Curry 56b. 1814 KY; farmer Susan Curry 51b. 1819 Penn Jackson S Curry 22b. 1848 IN Joseph C Curry 20b. 1850 IN Sarah J Curry 18b. 1852 IN ** Susan F Curry 16b. 1854 IN Margaret Curry 14b. 1856 IN Emma B Curry 8b. 1862 IN John F Foster 34b. 1836 IN
This matches with her parents' birthplaces in the 1880 Census.Oh, my, not to mention her parents are LIVING NEXT DOOR to the family in 1880:
Curry, Joseph H.66b. 1814 KY, parents b. VA Curry, Susan61 -wife-b. 1819 Penn, parents b. Delaware Curry, Emma B.18 -dau-b. 1862 IN