Georg Friedrich Kohlmann, a farmer, and his family settled in the Volga German colony of Rohleder on 14 July 1766. They are recorded there on the 1767 census in Household No. 34.
The 1767 census records that Georg Friedrich Kohlmann came from the German region of Zweibrücken.
- 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): Rl30.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 4 (Göttingen: Göttinger Arbeitskreis, 2008): 56.