He is married to Jacoba de Vries.
They got married on April 28, 1917 at Smallingerland (Fr), he was 21 years old.Source 3
grandparents
parents
brothers/sisters
children
Klaas de Jong | ||||||||||||||||||
1917 | ||||||||||||||||||
Jacoba de Vries | ||||||||||||||||||
Geboorteregister 1895, Achtkarspelen
https://www.graftombe.nl/names/info/100353/jong_de
Huwelijksregister 1917, Smallingerland