Biographical Sketch (1956):384 "Benjamin Foster, b. at Plymouth about 1654-5 (no record found). Approximate year of his birth is gleaned from the following Plymouth Colony Deed [II 2:28]: 27 June 1659 Robert Bartlett took a lease for ten years of the lands of his late son-in-law Richard Foster, agreeing to pay the latter's son Benjamin Foster, then aged 'foure yeares or thereabouts,' the sum of 8 pounds when he came of age [Mayflower Descendant 14:15]. On the same day, the widow Mary Foster and Jonathan Morey made an antenuptial agreement about bringing up the child Benjamin. One of the the conditions was that, if Mary died before Jonathan, Benjamin should be at the disposal of Robert Bartlett, Benjamin Bartlett or William Harlow (Plymouth Colony Deeds, II 2:28a; see Mayflower Descendant 14:16 for further details).

Bemjamin Foster died intestate in 1690, probably unmarried; no record of his death has been found. The inventory of the estate of Sergt. Benjamin Foster deceased, taken 16. Oct. 1690 [Barnstable Probate Records 1:36], shows an estate valued at £28.07.05; real estate noted was 25 acres upland at Monument and a whole share of land at Sippican. Inventory was sworn to by Jonathan Morey Jr. (his half-brother). No settlement of the estate was found."