Johann Conrad Engel and his second wife Anna Margaretha Ehring married in Hailer on 16 April 1722. Among their children was Georg Heinrich Engel, who was born 1 April and baptized 6 April 1732 in Hailer. Georg Heinrich Engel married Anna Margaretha Heil on 7 November 1765 in Hailer.
The Heil and Engel families arrived in Russia on 9 August 1766. Georg Heinrich Engel, Anna Margaretha, their son Conrad, and Anna Margaretha's mother Anna Catharina Heil are reported in Household #96.
Heinrich Engel, Margaretha Heil and their family are in Household #7 the Balzer 1798 Census, and their daughter Anna Margaretha Engel is in Household #18.
- Parish records of Niedermittlau (including Meerholz, Hailer, Neuenhasslau and Gondsroth) on Archion.de
- Parish records of Hailer on Archion.de
- Pleve, Igor. Lists of Colonists to Russia in 1766: Reports by Ivan Kulberg (Saratov: Saratov State Technical University, 2010) p. 266
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 1 (Göttingen: Göttinger Arbeitskreis, 1999): pp. 100-101
- 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): Volume 1, p. 256, 257