Who was his 1st wife (Mehitable?) and when was he married to her?
Nathaniel Fish was baptised on 20 Jun 1619 in East Farndon. He died in 1694. Nathaniel and his brothers John and Jonathan Fish were early inhabitants of Sandwich. Nathaniel and John Fish were each allocated 1-1/2 acres of meadow on 16 Apr 1640 in Sandwich. John, Jonathan and Nathaniel Fish are in the Sandwich section of the 1643 list of those between 16 and 60 able to bear arms in Plymouth Colony. Nathaniel was allocated 2 acres of meadow on 16 Apr 1640 in Sandwich. At the court held on 20 Aug 1644 Nathaniel was among those for whom a warrant was set forth to testify against John Ellis, accused of fornication with his later wife Elizabeth Freeman. John was publicly whipped. Servant Robert Ransom complained that he was badly treated by his master Thomas Dexter, Jr. The Court said that this could not be proved and Thomas Clarke of Plymouth bought out his time. On 4 Aug 1654, the Court warned Robert to improve his behavior and it fined Nathaniel Fish of Sandwich 20 shillings for entertaining Robert and abetting him in his stubbornness toward his master.
Is this the Nathaniel Fish you mean? I assume so.
Erica "the Disconnectrix" Howton and others work these families.