Marcus de Jong was married to Roosje de Groot. He was a smith fitter. On 6 March 1943 their daughter Renee was born in transit camp Westerbork.
Record of birth certificates of the Westerbork municipality, currently at the archives of Gemeente Midden-Drenthe in Beilen
In addition, a Jokos file (number 20388) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.