He is married to Trijntje Volkerts de Wit.
They got married on February 18, 1703 at Monnickendam.Source 1
Trouwen Gerecht: ... Jan Jacobsz Jonghman van Monnickendam ende Trijntje Volckers Jongedoghter uijt de Purmer in dese Stadts Jurisdictie ...They were married in church on February 18, 1703 at Monnickendam.Source 2
RK Huwelijk: sijn getrout Jan Jacobse en Trijn Volckers i facie Ecl:ae.