Johann Leonhard Haas, his wife Maria Esther, and their daughter Maria Esther (age 1) immigrated to Denmark (Schleswig-Holstein) arriving in Fridericia on 10 June 1760. They immigrated along with Maria Esther's children from a previous marriage: Johann Georg Ohler (age 7) and Maria Barbara Ohler (age 5). They are last recorded in the Danish colonies on 26 April 1763.
They joined the migration to Russia. Maria Esther is recorded on the 1775 census of Schilling in Household No. 28 remarried to Johann Nikolaus Fogler. Her children by Johann Leonhard Haas are recorded there also (Maria Esther, age 15; Anna Maria, age 12¼; Johann, age 8¼). The Ohler children do not appear to have made/survived the journey to Russia.
The Eichhorns record that Johann Leonhard Haas came from "Kanton Greichau (Kraichgau), Herrschaft von Baron von Venningen, Schwäbischer Ritterkreis."
- 1775 Census of Schilling (No. 28).
- 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-522.
- 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): Sg029.