Izaak Feitsma married Hanna Velleman in 1892. His first wife died in 1924. In 1925 he married Fijtje Viskoop. After her death Izaak married Rebecca de Leon in 1941.
Addition of a visitor of the website
Stadsarchief Amsterdam, archiefkaart Izaak Feitsma
In addition, a Jokos file (number 40711) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.