Johann Marx, a merchant (Kaufmann), and his family immigrated to Denmark (Schleswig-Holstein) arriving in the city of Schleswig on 20 May 1761.
They departed the Danish colonies on 2 June 1764 and joined the migration to Russia.
They settled in the Volga German colony of Rosenheim on 27 July 1765. They are recorded there on the 1767 census in Household No. 18.
The 1767 census records that Johann Marx came from the German Markgrafschaft Mühren and that his wife Barbara Matters came from the German village of Regensburg. The Eichhorns record that Johann Marx came from the German region of Bayreuth.
- Eichhorn, Alexander, Jacob & Mary Eichhorn. The Immigration of German Colonists to Denmark and Their Subsequent Emigration to Russia in the Years 1759-1766 (Deiningen, Germany: Drukerei und Verlag Steinmeier GmbH & Co. Kg, 2012): B-1034.
- Mai, Brent Alan. 1798 Census of the German Colonies along the Volga: Economy, Population, and Agriculture (Lincoln, NE: American Historical Society of Germans from Russia, 1999): Rm27, Rm59.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 4 (Göttingen: Göttinger Arbeitskreis, 2008): 66.