Nathan Swart was the fifth of the seven children of Salomon Swart and Grietje Deutz. He married Alida Krant, daughter of the coalman Jesaia Krant and Judith Peeper. The couple had two children, Sally and Jacques. Alida was a seamstress at the time of her marriage and Nathan a wall paperer.
Copies remain of Nathan Swart and Alida Krant's marriage certificate and of Sally and Jacques Krant's birth certificates.
In addition, a Jokos file (number 30118) on this family is at the Amsterdam Municipal Archive. Access is subject to authorization from the Stichting Joods Maatschappelijk Werk.