Jacob Swart was the third of the seven children of Salomon Swart and Grietje Deutz. He married Marianna Groen, daughter of the merchant Samuel Groen and Gesina Vuijsje, on 16 November 1932.
The couple had a daughter, Greta. Marianna was a seamstress of ladies' garments at the time of her marriage and Jacob a hairdresser.
Copies remain of the marriage certificate of Jacob Swart and Marianna Groen…