Jacob de Jong was a son of Abraham de Jong and Maaike Cohen. He married 20 October 1920 in Amsterdam to Roosje Naarden, a daughter of Jochem Naarden and Rachel Waas.
His siblings, who did not survive the Holocaust too were Hartog, Marianne, Benjamin, Anna, Wolf, Karel, Rosa and Esther. Two brothers have survived the war.
City Archive of Amsterdam, archive card of Maaike Cohen and website www.wiew…