Izaak de Jongh married Anna Blik on 18 December 1912. The couple had two children, Leon Izaac de Jongh born in 1913 and Hartog de Jongh born in 1917. Anna Blik died on 3 March 1942.
Izaak de Jongh married Rosalia Wrazlowsky in 1942 in Amsterdam.
Addition of a visitor of the website