Izaak de Vries was the son of Lazarus de Vries and Johanna Kamerling. He married Gonda Cats in 1896. She was the daughter of Heiman Cats and Rachel Bendien.
Addition of a visitor of the website
In addition, a Jokos file (number 36334) on this person is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.