There are two, presumably related Birsack families that settled in the Volga German colony of Keller.
(1) Johannes Birsack (age 28), a farmer, and his family are recorded in Keller on the 1767 census in Household No. 58.
(2) Philipp Birsack (age 23), a hosier (Strumpfwirker), is recorded in Keller on the 1767 census in Household No. 72.
The 1767 census records that both of these men came from the German village of Oberursel in Kurmainz.
Following the destruction of Keller, the Birsack family resettled to the colony of Neu-Kolonie.
- Mai, Brent Alan. 1798 Census of the German Colonies along the Volga (Lincoln, NE: American Historical Society of Germans from Russia, 1999): Nk17.
- Pleve, Igor. Einwanderung in das Wolgagebiet 1764-1767 Band 2 (Goettingen: Der Göttinger Arbeitskreis; 2001): 354, 357.