A24-41 in The Immigration of German Colonists to Denmark and Their Subsequent Emigration to Russia in the Years 1759-1766
B-305 in The Immigration of German Colonists to Denmark and Their Subsequent Emigration to Russia in the Years 1759-1766
Family #46 in the 1775 Grimm census.
Line #12 in the Appendix of the 1798 Grimm Census.
Johann Adam was born in 1745 to Christoph Eberhard and Margaretha Metz Eberhard, a Lutheran couple. Christoph was a farmer by trade. According to The Immigration of German Colonists to Denmark and Their Subsequent Emigration to Russia in the Years 1759-1766, the family were from Spoeck, Unteramt Staffort Oberamt Karlsruhe, in Baden-Durlach. 
The family was one of a group of Germans who first immigrated to Denmark, before eventually immigrating to Russia.
For the Danish part of their journey, the family left the collection point in Altona with their guide Johann Thomas Gabler.  They arrived in the City of Schleswig on 04 July 1761.  There were six people in the Eberhard party; Johann Adam's parents and four children.  Johann Adam was 17 when he arrived in Denmark and had just married Catharina Metz.  Also traveling with the family were his younger sisters Christina, age 13, and Anna Maria, age 9. 
After the family's arrival, Johann Adam and his wife Catharina lived at a separate residence at Number 4 Cimbrien in Colony G9 Christiansholm, in the region of Gottorf. 
As did most of the German immigrants, they found it difficult to farm the marshy Danish lands given to them. When Catherine the Great issued her manifesto inviting Germans to immigrate to Russia, they joined a large group of other disatisfied Germans who chose to move to another new country rather than return to Germany. He and his wife left Denmark on 07 January 1765 with the destination of Grimm, along with his father. 
Adam's first wife Catharina Metz died in 1763. He married Katharina Kaiser in Denmark, in part to have someone help care for his infant son. Adam Eberhard appears in the 1775 census with his second wife Katharina and six children:
1775 Grimm Census 
He does not appear in the 1798 census. His widow, Katharina is documented as having married Just Jung from Schwab and taking son Heinrich and daughter Susanna to live with her in Schwab in 1788.  This indicates that Adam Eberhard died before 1788.
Note: The Christoph Eberhard who appears in the 1798 census is the brother of Johann Adam, not his father, as implied by the Origins project source listed in the sources. 
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