Tompkins County was formed by taking the towns of Hector, Ulysses and Covert from the County of Seneca, and by taking the town of Dryden and parts of the towns of Locke and Milton from the County of Cayuga. The part of Locke set off to Tompkins was named Division, and the part set off from Milton was called Lansing.
The County first consisted of six towns: Hector, Ulysses, Dryden, Division, Lansing and Covert. The Town of Division was later changed to Groton. April 13, 1819 the Town of Covert was taken from Tompkins and re-annexed to Seneca.
March 16, 1821 the towns of Ithaca and Enfield were formed by dividing the town of Ulysses, and March 22, 1822 the towns of Caroline, Danby and Cayuta were taken from the County of Tioga and annexed to the County of Tompkins. The name of the town of Cayuta was afterwards changed to Newfield.
June 4, 1853, a narrow strip was taken from the west side of Newfield and annexed to the town of Catherine in Chemung County. April 17, 1854, the County of Schuyler was formed and the town of Hector was taken from Tompkins County and annexed to Schuyler.
For persons attempting to locate the estates of people who died before 1854, please make sure you are checking the correct county of residence. For example, if a person died a resident of the Town of Hector prior to 1817, it may be necessary to check the records in Seneca County. Also, for a person who died a resident of Hector after April 17, 1854, it may be necessary to check the records in Schuyler County.