On 22 Apr 1726 Japhet first married Thankful Dickinson (26443) , daughter of Nathaniel Dickinson (10454) (1 May 1663-Oct 1751) & Hepzibah Gibbs (12 Jan 1664/5-26 Jun 1713), in Springfield, Hampden County, Massachusetts. Born on 11 Sep 1702 in Hatfield, Hampshire County, Massachusetts. Thankful died in Chicopee, Hampden County, Massachusetts, on 17 Mar 1733; she was 30.

On 28 Oct 1778 Japhet second married Lydia Todd (53085) , daughter of Samuel Todd (36431) (1 Jul 1672-Dec 1741) & Susanna Tuttle (20 Feb 1679[/80]-10 Oct 1737), in Springfield, Hampden County, Massachusetts. Born on 28 Jul 1699 in New Haven, CT.56 Lydia was baptized in First Congregational Society, New Haven, in Jul 1699.55 Lydia died on 16 Jun 1790; she was 90.55