William was mentioned in the 10 October 1690 will of his father, Thomas St. John, proved on 10 September 1698. “likewise my Will is that all my Land that I am now possessed with to be equealy devided between my Sons Thomas St: John Junr: & William St: John I do likewise make them both at age at Eaighten years if there Mother should decease or Marrey but if not to abide while ye Age of one & twenty … I give & bequeath unto Wife Mary St: John all ye rest & remaing part of my Estate both movables & unmovables dureing hur life time provided that she shall keep herselfe a widoo & not marrey & after my wifes desese to be eaqually devided amoung all my Cheldren but if my Wife Should Marrey then my will is that Shee Should have but ye thurd part of my Easeteat & ye other to be devided amoung my Cheldren”. [Essex County, Virginia, Deed Book 9, page 225.]

On 9 September 1699, Mary St. Johns of Southfarnham parish in ye County of Essex, widow, for love good will & affection wth: I have & bear unto my two Dear & Loveing Sons Tho: St: Johns & Wm St Johns both of Southfarnham parish & County of Essex, give all that plantation and Land wch: I now Live upon wch: my Late Husband Tho: St: Johns since deced formerly bought of Coll: Wm: Claibourn lying in Southfarnham parish as Also that tract wch ye sd: Mary St. John Lately bought of Mr Richard Covington all wch: sd: plantation & Land doth Contain by Estimation two hundred and fifty Acres more or Less., to be Equally divided betwen ye sd Tho: St: Johns & Wm: St: Johns, and that ye sd Tho: St: Johns Shall Enjoy one halfe of ye Orchard belonging to ye Sd: plantation after ye sd: Mary St: Johns decease and further yt: my Daughter Eliz Cooper ye now wife of Wm: Cooper Shall have free Liberty her & her Husband dureing her Naturall life to remaine abide & be upon ye sd plantation where they are now Seated, but if in Case ye Surviver be Sd. Husband Wm: Cooper to have ye Same priviledg upon ye Sd plantaton during her [sic] Naturall life According to a Lease Instrument or writing Signed Sealed & Delivered unto ye sd Wm. Cooper & his wife by Tho St: Johns my Late Husband, & further yt my two Sons Tho St: Johns & Wm: St: Johns Shall have free priviledg & Liberty to Seat upon ye Land when Each of them Shall Attaine unto ye age of Eighteen yeares. Signed Mary her H mark St: Johns. Witnesses: Edward Danelane, Jno: Prosser. On 10 September 1699 ordered to be recorded. [Essex County, Virginia, Deed Book 10, page 36.]

On 19 March 1733, Thomas Edmondson, Thos Cleman jr, Jeremiah Sheppard jr and a Wm St John were bound £600 current money for Thomas Edmondson’s administration of the goods, chattles and credits of Samuell Edmondson deceased. [Essex County, Virginia, Will Book 5, pages 211–212.]