I do not find him in either the 1860 or 1870 census in the United States.

I suspect he came over from France sometime in the early 1870's.

I suggest you center your search through the Old Courthouse Museum in Vicksburg.

1880 United States Federal Census about Francis Greffoz
Name: Francis Greffoz
Home in 1880: Vicksburg, Warren, Mississippi
Age: 53
Estimated birth year: abt 1827
Birthplace: Paris
Relation to Head of Household: Self (Head)
Spouse's name: Annies
Father's birthplace: Paris
Mother's birthplace: Paris
Occupation: At Home
Marital Status: Married
Race: White
Gender: Male
Household Members:
Name Age
Francis Greffoz 53 At Home
Annies Greffoz 36 Milliner born in France, 1844
Ernestine Greffoz 6 At School born in Mississippi 1874
Victor Greffoz 2 born in Mississippi 1878
Hattie Taylor 50 Servant