Ontario County, NY

History

Transfer of what is now Ontario County to New York formally took effect in 1789, when native title was extinguished, and the county was formally established to govern the lands of the Phelps and Gorham Purchase the year prior. The territory first organized as Ontario County was much larger than at present and ran south from the shore of Lake Ontario. As the area was settled, new counties were organized. The following counties were rapidly organized from this territory in the first decades after the war: Allegany, Cattaraugus, Chautauqua, Erie, Genesee, Livingston, Monroe, Niagara, Orleans, Steuben, Wyoming, and Yates counties, and parts of Schuyler and Wayne counties.

In 1796, Ontario County was divided and Steuben County was organized. In 1802, Ontario County was reduced when Genesee County was split off. The new county was originally very large, including the present Allegany, Cattaraugus, Chautauqua, Erie, Niagara, Orleans and Wyoming Counties and parts of Livingston and Monroe counties.
Source: Wikipedia

Modern Day Adjacent Counties

Wayne County - north
Seneca County - east
Yates County - south
Steuben County - southwest
Livingston County - west
Monroe County - northwest

Gleanings from

• Ontario Co., NY - Probate Records
  • 1813 Will - Silas Reeves