Il est marié avec Constantia Margaretha Kolff.
Ils se sont mariés le 21 mars 1774 à Amersfoort, il avait 25 ans.
Enfant(s):
baljuw 1768-1795, schout, 1768-1795, 1796-1798, 1798-1811, 1817, adjunct-secretaris 1771-1789, secretaris 1789-1795, 1797-1798, 1798-1811, 1817-overl., rentmeester 1789-1795, thesaurier 1796-1798, burgemeester 1817-overl. and reder at Middelharnis.
Gualtherus sons Adrianus Quirinus (CB XIIf) (1745-1826)Middelharnis: Kolff swan and grapes and Lambertus (CC XIIg) (1749-1823) complemented, just like their grandfather and their father before them, public with private entrepreneurship. Priorities could differ between the two. Apart from being appointed as juror, sheriff, bailiff, secretary, treasurer and mayor, secretary and dike-reeve of polders, notary public and commissioner of ground-taxes, the brothers were also ship owners. As Lambertus was mainly regent and gouvernor, Adrianus Quirinus was more the entrepeneur and a man of Enlightenment. In 1768 the latter bought the big house at the Voorstraat, with warehouse and carriage houses, as well as the wine company already established there, and the grounds that were part of it. Still today one can see at the door this year inscribed over a sculptured bunch of grapes, and above this door the coat of arms of the Kolff family. Apart from him being merchant he also had income from agriculture. Notable are his philantropical and cultural activities. Let me start in writing about Adrianus Quirinus' societal interest and after that about his economical activities, which would lead - in the course of a number of generations - to some kind of collective company.
Les données affichées n'ont aucune source.