Zacharias van Praag was a son of Henri van Praag and Betje Samson van Bever. He married 27 August 1876 in Zaandam Schoontje Geleerd, a daughter of David Levie Geleerd and Judic Eliazer Drukker. The couple had six children: Evalina, Betje, Henri, Levie, Louis en David.
City Archive of Amsterdam, family registration card of Zacharias van Praag and website www.wiewaswie.nl.