The Seneca County Museum is the former home of local businessman Rezin W. Shawhan. Born in 1811, Shawhan arrived in Tiffin in 1832 and opened a store with his brother Lorenzo. The store's success enabled Rezin to expand his interests into real estate and banking. Upon his death in 1887, his estate was valued in excess of $1 million. Much of it was bequeathed to his second wife, Della Watson Shawhan. He also left bequests to Heidelberg College, the library, and Tiffin's churches. The Greek Revival-style house, built in 1853, was passed down through the family, ending with Lynn Troexl who, in 1941, donated it to the county for use as a museum. The house is part of the Fort Ball-Railroad Historic District, listed on the National Register of Historic Places in 1979.