Isaak Nussbaum (1872-1941), along with his brothers Ruben (1865-1936) and Levi (1876-1931), came to Oschersleben in the 1890s as young men from Burghaun in Hesse. In 1894  Isaak Nussbaum, together with his brother Ruben, registered the “Operating of a Livestock Business” in Berliner Strasse No. 45.During World War I. they bought agricultural estates which were in financial difficulty and purchased large amounts of arable land on the outskirts of Halberstadt. They hired young specialists trained in the modern methods and observant Jews from the East to work in the administration. In Halberstadt, the Nussbaums ran the Siechenhof dairy farm which produced kosher milk and dairy products according to the kashrut, or Jewish dietary laws, for the Jewish community in Halberstadt.The Halberstadt business offices of the Nussbaum & Friedmann company were located at Friedrichstrasse No. 4 (today Schwanebeckerstraße), where a prayer room was also installed. This private synagogue was also a symbol of their social status. The Nussbaums were looked upon as upstarts by the local long-established families in Halberstadt and had to prove themselves in the Jewish community.