Seneca County, New York
Seneca County is a county located in the U.S. state of New York. As of the 2010 census, the population was 35,251. The primary county seat is Waterloo, moved there from the original county seat of Ovid in 1819. It became a two-shire county in 1822, which currently remains in effect, using both locations as county seats although the majority of Seneca County administrative offices are located in Waterloo. Therefore, most political sources only list Waterloo as the county seat. The county's name is from the Iroquois (Seneca) that occupied part of the region.
The area covered by Seneca County straddles the prehistoric territories of both Seneca and Cayuga Nations of the Iroquois League. When counties were established by Europeans in New York in 1683, the present-day Seneca County was part of Albany County. This was an enormous county, including the northern part of New York as well as all of the present state of Vermont and, in theory, extending westward to the Pacific Ocean. This county was reduced in size on July 3, 1766 by the creation of Cumberland County, and further on March 16, 1770 by the creation of Gloucester County, both containing territory now in Vermont.