The Ohio Department of Agriculture maintains a program called Ohio's Historic Family Farms. They recognize the many social, economic and historic contributions made by Ohio's founding farm families and created this program to honor these families for their enduring legacy.
The program grants three designations based on the number of years of same-family ownership:
Century Farms (100-149 years);
Sesquicentennial Farms (150-199 years); and
Bicentennial Farms (200 years and more).
Here is the application to download, print, and complete: http://www.agri.ohio.gov/publi