Terry, yes, the "James SANDERS" you found on the 1880 Census is the correct SANDERS. I confirmed this with the finding of Wesly GRIFFIS and Nancy on the 1900 Census. this family is enumerated as follows;
1900 US Census, Marshall, Tennessee
GRIFFIS, Wesly W., head, m, 72, married 4 years
Nancy J., wife, f, 43
SANDERS, Forest, step-dau, f, 21
Velerna W., dau, f, 3
Vester, dau, f, 1
Notice on this census we have "Forest SANDERS", step-dau to Wesly GRIFFIS. Now going back to the 1880 Census where you found James SANDERS. that family is enumerated as follows;
1880 US Census, Giles, Tennessee
SANDERS, James, head, m, 26
Nancy, wife, f, 24
Bettie, dau, f, 4
Ainer, dau, f, 2
Forest, dau, f, 1
So this "Forest SANDERS", 1 year old in 1880 would most likely be the same "Forest SANDERS", step-dau to Wesly GRIFFIS, 21 years old in 1900.
There is reference to a marriage record in Giles, Tennessee for a "J. L. SANDERS" and a "N. C. Burgess". This is most likely the marriage of James and Nancy, 10 Aug 1874. Need to confirm this with primary sources in Giles.
Nancy Caroline GRIFFIS, death is recorded on 25 Oct 1943 in Marshall, Tennessee. Her birthdate is listed as 18 Mar 1856 in Marshall, Tennessee. Her father was listed as Tom Burgess and mother as Eliza Massey. Again, this information should be confirmed with primary sources and provides secondary source information of her birth and her parents.
Hope this has helped, good hunting, William Perry