Yakob's town of Wloclawek was located on the Vistula River. He and his brother Abraham studied Hebrew and German in addition to Polish. Yakob met his bride Machla through a Jewish matchmaker, and after marrying they lived in Lodz. Yakob ran the family textile business until 1938, when he invested in real estate. He became landlord of an apartment building, where he and his family also lived.

1933-39: When the Nazis expelled the Polish Jews from Germany in 1938, Yakob established a relief organization in Lodz to arrange subsidized medical care for the new refugees. After the Germans occupied Lodz in 1939, Gestapo agents checked on him frequently. One day they took Yakob for interrogation at their office in a confiscated Jewish school building. His terrified family was overjoyed when he was allowed to return home.