Isaac de Vries was the son Simon Isaac de Vries and Rachel Mozes du Mosch. Isaac was married and had two children. His youngest, Hermanus Salomon de Vries lived at another address together with his family. The whole family died in the war.
Isaac de Vries, his brother and father were partners in a dry goods business called S.I. de Vries.
Addition of a visitor of the website
According to a list with shops of Jewish owners, compiled by the Amsterdam police in 1940, this family had a fashion shop, address: Willemsparkweg 164 in Amsterdam.
Abstracts of the police archives which are currently at the Amsterdam municipal archives