There are two Gropp families recorded on the 1767 census of Balzer. The 1767 census does not record a relationship between these two families.
(1) Jakob Gropp, a farmer, and his family settled in the Volga German colony of Balzer on 28 March 1766. They are recorded there on the 1767 census in Household No. 31. The 1767 census records that Jakob Gropp came from the German region of Kurpfalz.
(2) Johannes Gropp (age 12), the orphaned son of Johannes Gropp, is recorded on the 1767 census of Balzer in Household No. 67 along with the Andreas Grün family. The 1767 census does not record a relationship between the Gropp and Grün families. This Johannes [Konrad] Gropp is recorded on the 1798 census of Balzer in Household No. Bz032.
- 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): Bz032.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 1 (Göttingen: Göttinger Arbeitskreis, 1999): 80, 91.