Wendel Flack and his family immigrated to Denmark (Schleswig-Holstein), arrivin gin Fridericia on 19 January 1761. They are last recorded in the Danish colonies on 26 April 1763.
Wendel's son, Adolph Flack, a farmer, and his family settled in the Volga German colony of Rosenheim on 27 July 1765. They are recorded there on the 1767 census in Household No. 28.
In 1797, Johann Gottlieb Flack moved from Rosenheim to Reinwald.
The 1767 census records that Adolph Flack came from the German village of Zell in Grafschaft Erbach and that his wife came from the German region of Darmstadt.
Various documents record this surname as Fleck, Flech, Flenk, Flach, and Flack.
- 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-390.
- 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): Rw38, Rm23, Rm55, Mv2481.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 4 (Göttingen: Göttinger Arbeitskreis, 2008): 68