By the mid 1800s, there was very little land left in Germany that hadn’t already been divided up into small parcels. It was difficult to make a living at farming, and being able to own a large and successful farm was often the ultimate dream of German men. Due to the scarcity of farm land in Germany, however, many Germans took up more artisanal occupations like shoemaking, woodworking, tailoring, linen weaving, etc. In Dr. Teva Scheer’s book, “Our Daily Bread,” she explains that since Germany was a late comer to the Industrial Revolution, there was not much of a market economy in Germany, and villages would mostly have to produce everything for themselves. Thus, each village could have one or more shoemakers, woodworkers, tailors, linen weavers, etc.
When these Germans immigrated to America, the situation was often quite the opposite. Land was so plentiful and affordable that Germans could acquire huge swathes of land at a fraction of what it would have cost them in Germany. Furthermore, since America already had a large scale market economy, there was less demand for the sort of artisanal trades that many Germans had. Not every town needed a shoemaker, linen weaver, etc. Those goods could be gotten from other towns that specialized in producing those goods. Instead, the job opportunities were largely in farming and mining.
Thus, when German immigrants arrived in America, their previous training often fell to the wayside, and they mainly took up farming and mining for a living. So, when you find a German immigrant ancestor who farmed or mined in America, don’t assume that they had the same occupation back in Germany. Or, if you find an ancestor in Germany who worked as a cooper or a carpenter or a glazier, don’t assume that that is how they made their living after immigrating to America. They might have kept that occupation after immigrating, but there is a very good chance that your German ancestor became a farmer or miner in America, as that is where the demand for jobs was in the 18th through 20th centuries.