Hi Julie, I have some information on Garrett C. Briggs. I found this while searching my line. Let me know if it helps, I'm also doing the Briggs line from Madison and Yancey counties. Maybe we can share notes. I found this in the 1860 Madison co. census.
William K.M. Briggs (33) M. Lavade (24) 1.Elizabeth Briggs (9) 2.Mary T. Briggs (6) 3.Harett Briggs (5) 4.Henry C. Briggs (4) 5.Garrett C. Briggs (3) 6. Calidona Briggs (1)