I was just in Knox County 2 weeks ago and got several Marriage Bonds and I believe that they start in the mid 1800's. Someone took several of their Bond Books right out from under their nose one day the clerk told me. I was looking for my GG Grandparents Lewis and Phoebe Bennett Sears and that was one of the books. That was the 1840 Book. But they have them in the 1850's. Pati Sears-Burnett