If your ancestors were early settlers of Cayuga County in Central ("Upstate") New York, it is important to understand the who, what, where, when, why and how the towns were established. This is an essential part of finding records about our ancestors and is likely to be the cause of some brick walls. Are you looking in a town that was called by another name at the time your ancestor lived there?
For example, ALL of central and western New York was considered Albany County until 1772, so if you're researching central New York ancestors who lived before 1772, look in Albany County's records.
In 1772, most of western New York became Tryon County, so if you're looking for records between 1772 and the 1780s, try looking in Tryon County's records. From there, more divisions took place. In 1784 the name of Tryon County was changed to Montgomery County. Montgomery County was divided in 1788 to form Ontario County, and again in 1791 to form Herkimer County.
In 1794, Onondaga County was formed from Herkimer County. The above map shows how the towns were laid out at the time. Cayuga County was formed from Onondaga County in 1799. In 1804 Seneca County was formed from part of Cayuga County, and on April 8, 1808, Cortland County was formed from part of Onondaga County. In 1817 Tompkins County was created from southern portions of Cayuga and Seneca Counties.
When Cortland County was established in 1808, it consisted of the townships of Virgil, Cincinnatus, Homer, Solon, and the southern half of Tully and Fabius.
Homer was formed in 1794. Solon, Little York, East Homer, and Virgil were all formed from Homer. Harford was formed from the southwest quarter of Virgil and Lapeer was formed from the southeast quarter, both in 1845. Hunts Corners was a part of Lapeer. Then, in 1829 Cortlandville was formed from the southern half of the original township of Homer and the northeast corner of Virgil. Cortland Village, McGrawville (McGraw), South Cortland, and Blodgett Mills were all part of Cortlandville.
Solon was formed from Homer in 1798. Cincinnatus (Military Tract #25) was formed from Solon in 1804. In 1818, Cincinnatus was divided to form Freetown, Willett, and Marathon. A portion of Solon was annexed to Truxton in 1811. Taylor was formed from Solon in 1849 and included Taylorville and Union Valley within its boundaries.
When Cortland County was formed in 1808, Preble was formed from the southern half of Tully. Preble Corners and Baltimore were parts of Preble. Scott was formed from Preble in 1815. Also upon the formation of Cortland County, Truxton was formed from the southern half of Fabius. Cuyler was formed from Truxton in 1858.
For more information, this 1860 book "The Historical and Statistical Gazetteer of New York State", by John Homer French, gives a summary of each town's history. Following is the chapter on Cortland County for quick reference:
You can find and read the entire book online for free at Archive.org.