Seneca County, Ohio: History
This area was long occupied by a succession of indigenous peoples. During and after the colonial period, French, British and American fur traders established relations with the historic peoples of the time.
The county was barely inhabited by European Americans until the 1830s, but this period was one of steady migration by settlers from New York and New England. The migration was stimulated by completion of the Erie Canal through New York, which connected the markets by the Great Lakes to the Hudson River and New York City. By 1860 the population of Seneca County had increased to about half the current number of residents. It was developed for agriculture, and grew slowly thereafter. In 1889 900 Luxembourgers settled in Seneca County where they built substantial churches and schools.
Toward the end of the 19th century, during the Great Depression, and the post–World War II baby boom, this area had periods of greater population increase. In 1980 the census recorded a population of 61,901; the total has since declined. 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.