I don't know if this applies to you but since Foncannon is such an unusual name I thought you might like the information.I was looking over some of my records and came across the name Foncannon.If I find an unusal name I check Genforum to see if I can help someone out.
From,1900 CENSUS DADE County Missouri Volume(Center Township, includes city of Greenfield) p.40
Foncannon, Madison headW M Jun 1849 50 M28IN MD PA farmer Mary F. wifeW F Jan 18550 M28 2-2 VA VA VA Cora S. dauW F Sep 1872 27 SIL IN VA
The columns read: name, relationship, color, gender, birthdate, age, marital status, children's gender, birthplace, father's birthplace, mother's birthplace.On mary they left the last digit off of her birth year.Where is says 2-2, I surmised that that is children's gender because that number only appears next to women's names.
I am not a Foncannon but am a native of Dade County.I live in South Korea so I only have access to records that has my families name on the same page.