In the first years the Jews of Zündorf were considered to be „small people“ who only appeared as businessmen.
However, bit by bit the Jews became more and more important.1900 many important local industrial businesses were established in Porz, e.g. steam plane factory and saw works A. Dülken & Co, Hauptstr. 14 in Porz and the insulating factory of Meirowsky in Kaiserstrasse eastward of the train station, Thereby engineers, chemists and doctors with occupational status and who were in funds moved to Porz: All of their children were sent to the secondary school established in 1908. During the First World War a senior physician received the iron cross in 1914.
After the end of the First World War the financial situation got worse. In 1921 the Jewish municipality wanted the office of mayor Wahn to finance a subsidy in the amount of money the jollity tax brought in for this purpose. They did so, because it became necessary to renew the synagogue; however, their application was rejected.