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
Renee de Jong, daughter of Marcus de Jong and Roosje de Groot, was born on 6 March 1943 in Westerbork transit camp and she died there on 14 April 1943. She was cremated on 15 April 1943. The urn with her ashes was placed on the Jewish cemetry in Diemen on field U, row 3, grave nr. 5.
Register van joden die in het kamp Westerbork zijn gecremeerd, 1943-1944; archief van de gemeente Westerbork, opgenomen in het archief van de gemeente Midden-Drenthe te Beilen, inv. n 3789
Lijst van in de concentratiekampen Westerbork en Buchenwald overleden Joodsche Personen die op Nederlandsche begraafplaatsen ter aarde werden besteld; NIOD, archief Westerbork, port. 1, map 1