Seneca County, Ohio

Seneca County is a county located in the U.S. state of Ohio. As of the 2010 census, the population was 56,745. Its county seat is Tiffin. The county was created in 1820 and later organized in 1824. It is named for the Seneca Indians.Seneca County comprises the Tiffin, OH Micropolitan Statistical Area, which is also included in the Findlay-Tiffin, OH Combined Statistical Area.HistoryThe county was barely inhabited until the 1830s, but by 1860 its population had massively increased to about half the current number of inhabitants. It grew slowly thereafter, with periods of more marked increase towards the end of the 19th century, during the Great Depression and the post–World War II baby boom. In 1980 it was censused at 61,901, and has been declining since. Since about 2000, the county's population declines by about 100–300 persons annually, mainly due to a migration deficit of about 300 persons annually. This decline is projected to continue in the future.GeographyAccording to the U.S. Census Bureau, the county has a total area of, of which is land and (0.3%) is water.