A20-7 in The Immigration of German Colonists to Denmark and Their Subsequent Emigration to Russia in the Years 1759-1766,.
B-1061 in The Immigration of German Colonists to Denmark and Their Subsequent Emigration to Russia in the Years 1759-1766.
Rus14-20 in The Immigration of German Colonists to Denmark and Their Subsequent Emigration to Russia in the Years 1759-1766.
Family #39 in the 1775 census.
Family #61 in the 1775 Grimm census.
While not confirmed, all records seem to point to Anna Margaretha Kaltenberger being the daughter of Rosina and Michael Kaltenberger or Michael Kaltenberger's younger sister. The couple were Lutherans from the Baden-Durlach Margraviate. A surname search using her married name shows no Kaltenbergers, but there are Kaltenbachs. I may have found the christening record for her Anna Margaretha's father or brother, also a Grimm resident, Michael Kaltenberger.
Alternatively, Anna Margaretha may have Michael's sister. Both immigrated first to Denmark and then to Grimm, Russia. Anna Margaretha accompanied Alexander Meisner as his fiancee and they married in the town of Kropp.
Rosina and Michael Kaltenberger were scheduled to leave for Denmark on May 5, 1761, with Johann Andreas Kirchhof leading their convoy, but for some reason they remained behind. It was most likely to witness the marriage of Anna Margaretha to Alexander Meisner. The newly wed Meisners arrived in Denmark on May 18, 1761,  and Rosina and Michael probably tagged along in that convoy, even though they are not specifically mentioned on the transportation list. They obviously arrived in Denmark one way or another and are listed in Danish records as German immigrants.
Anna Margaretha and her husband arrived in the City of Schleswig on 30 May 1761, and they took their oaths of allegiance on 24 July 1761.  Two weeks later they had settled in a 1 Gottes Wache in Colony G14 Julianenebene, in the district of Gottorf.  Their first child, daughter Elisabeth Meisner, was born in 1762. 
The marshlands were very inhospitable to farmers. Although the Germans were good farmers with typical farm land, it was far more difficult to convert these former wetlands and grow crops. Most of the German immigrants barely reaped enough to feed their families, let alone to provide food for others in Denmark. When Catherine the Great invited Germans to immigrate to Russia, Alexander and Anna Margaretha decided it offered them a better opportunity to provide for their family.
Rosina Kaltenberger passed away prior to 1775. She is not specifically mentioned in the 1775 census, but her husband is. She probably departed from Denmark by 1765, but it's not clear if she survived the trip to the Volga River. If she did survive the perilous journey, there is no telling how much time passed before she died. By the time the census was taken in 1775, her husband had remarried Juliana Wittman, age 17, and the couple had a 1-week old baby named Johann Michael. Because of Juliana's age, she probably hadn't been married to him for longer than a year. This means that Rosina could have survived up to 1773 or 1774. However long she lived, she did not have any children with Michael, as there are none listed as belonging to her in the 1775 census. Her only possible child known thus far is Anna Margaretha, and that has not yet been confirmed.
Anna Margaretha married fellow traveler Alexander Meisner, with whom she had three children. Alexander died before the 1775 census was taken, and his widow remarried Johannes Kaiser. They are listed together in the 1775 census entry for their family.
1775 Grimm Census 
Anna Margaretha was no longer living in 1798, and her husband had remarried to Katharina Müller. All the children in the 1798 census belonged to Anna Margaretha, and the youngest was 5 years old. This means she died between 1793 and 1798. A summary of the 1798 census entry for her husband is shown below to connect her to her children with Johannes Kaiser. It was already shown in the 1775 census that she had 3 children with her first husband Alexander Meisner.
1798 Grimm Census 
Possible Birth Record for Johann Michael Kaltenbach 
In the possible birth record above for Rosina's husband shown above, it states that he was from the town of Haslach (A. Wolfach). I did an Internet search for the town of Wolfach. It is a small town in southwestern Germany near the French and Austrian border. I did a search on the town, and found this description in the German version of Wikipedia:
This is important because my grandfather, Alex Kaiser Kaiser-1024, told me personally that his family was from the Black Forest region of Germany. This is something that was passed down from generation to generation, and he was passing that information down to me, the new keeper of the family genealogy information. Thus far, none of his ancestors was from a town in the middle of the Black Forest. I know this story sounds anecdotal, but Alex Kaiser was a veritable scholar about all things Volga German. From 1940 to 1970 he made many speeches around the midwest United States about the Volga Germans and their history, and this Black Forest detail has always remained the same.
If this birth record is a match for Johann Michael Kaltenberger, this could be the Kaiser family's connection to the Black Forest area.
Additional support for a connection with this family is the DNA report for two family members that shows French heritage. No other family members account for that DNA. The town of Wolfach was near the French and Austrian borders. The border between France and Germany was porous and people went back and forth across it through the years in search of food and work. Intermarriage with someone of French heritage could explain the DNA markers that appeared in those DNA test results.
The American Historical Society of Germans from Russia (AHSGR) commissioned researchers to search for the origins of the Volga Germans in Germany. Their German Origins project has these notes on Michael Kaltenberger, Rosina's husband: 
Michael was old enough to be the father or sister of Anna Margaretha Kaltenberger, age unknown. What we do know is that she married Alexander Meisner in Kropp, Germany, in May of 1761, shortly before the couple immigrated to Denmark. Alexander Meisner was 28 years old that year. If Anna Margaretha was a young 16-18 years old, Michael could have been her father. If she was older, he was more likely her brother. That they both ended up in Grimm, Russia, was not coincidental.
Alexander Meisner died while in Denmark. He is not listed in the Volga Colony Departure Lists in The Immigration of German Colonists to Denmark and Their Subsequent Emigration to Russia in the Years 1759-1766. Anna Margaretha is listed in entry Rus 14-20 on page 673, right above the entry for Michael Kaltenberger, Rus 14-21. The list is not alphabetical, but it appears to keep families grouped together: The Tumlers, the Fritzlers, The Ramigs, the Schaefers, and the Kaltenbergers, for example. Anna Margaretha's second married surname is included in the entry (Keiser [sic]), but it appears that is for the researcher's convenience, so they can track her once she arrived in Grimm. There is no Johannes Kaiser/Kayser/Keyser/Keiser anywhere in that reference material who matches the age of her future husband.
The birth of her third child in 1767 doesn't seem to match up with the year her husband Alexander probably died. There are several possibilities:
Anna Margaretha and Johannes Kaiser's first child wasn't born until 1784. Even though she arrived in Grimm by 1766, she may not have remarried until 1775, when she would be listed in the census as Johannes' wife and her children as his step children. It is likely that Michael and Rosina helped her raise her children during the years in Grimm.
Anna Margaretha and her second husband, Johannes Kaiser, are the apparent ancestors for my Kaiser line of descendants in Grimm. By 1798, Anna Margaretha had passed away, but she left three Kaiser children behind:
Unfortunately I can find no other information about Michael's children with Rosina or his parents. No birth record for Anna Margaretha has been found yet. I also cannot locate a marriage record for Michael and Rosina.
I will continue to research these people along with Johannes Kaiser, Anna Margaretha's husband in Grimm.
Have you taken a DNA test? If so, login to add it. If not, see our friends at Ancestry DNA.
Margaretha is 25 degrees from Isaac Asimov, 30 degrees from David Attenborough, 26 degrees from Bill Bryson, 26 degrees from Richard Dawkins, 34 degrees from Bengt Feldreich, 36 degrees from Ruth Gates, 30 degrees from Stephen Hawking, 35 degrees from Julius Miller, 25 degrees from Bill Nye, 29 degrees from Magnus Pyke, 29 degrees from Carl Sagan and 23 degrees from David Randall on our single family tree. Login to find your connection.