The church records of Gedern report that Johann Peter Hartmann (son of Nicolaus Hartmann) and Elisabeth Lambmann (daughter of Johannes Lambmann) were married there on 26 January 1736. Elisabeth had been baptized there on 28 January 1714.
The births of ten of their children are recorded in the Gedern parish records: (1) Christoph Ernst, 21 October 1736 (died); (2) Johannes, 26 April 1738 (died 15 August 1745); (3) Catharina Christina, 28 October 1740 (died 1 August 1740); (4) Johann Engelhardt, 26 June 1742; (5) Juliana Catharina, 16 February 1744 (died 3 March 1749); (6) Severin, 12 December 1745 (died 12 June 1765); (7) Johannes, 19 November 1748; (8) Adam Christoph, 16 February 1751 (died 10 December 1756); (9) Heinrich, 21 October 1753; and (10) Johann Christian, 14 July 1756.
Elisabeth death on 3 September 1761 is recorded in the Gedern parish documents.
Peter and the surviving children immigrated to Russia, arriving from Lübeck at the port of Oranienbaum on 4 July 1766 aboard the ship Der Junge Mathias under the command of Skipper David Wollert. They arrived in the Volga German colony of Reinwald on 24 June 1767 and are recorded there in Household No. 55.
Also settling in Reinwald was Johannes Hartmann, son of Johann Paul Hartmann and Maria Dorothea Lambmann, who was baptized on 2 December 1746 in Gedern. He arrived from Lübeck at the port of Oranienbaum on 4 July 1767 aboard the English frigate Love & Unity under the command of Skipper Thomas Fairfax as the servant of Johann[es] Barth. He is recorded with his wife Magdalena in Household No. 48 of the 1767 census of Reinwald.
In 1787, Johann Weigand Hartmann moved from Beauregard to Reinwald. In 1790, Johann Hartmann moved from Reinwald to Philippsfeld.
- Mai, Brent Alan. 1798 Census of the German Colonies along the Volga (Lincoln, NE: American Historical Society of Germans from Russia, 1999): Ks028, Pp16, Rw26, Rw27, Mv0176, Mv2406.
- Parish Records of Gedern.
- Pleve, Igor. Einwanderung in das Wolgagebiet, 1764-1767 Band 4 (Göttingen: Göttinger Arbeitskreis, 2008): 42 & 44.
- Pleve, Igor. Lists of Colonists to Russia in 1766 (Saratov: State Technical University, 2010): #1605, #1903.