John is a fifth generation farmer on the same land on which his great-great-grandparents settled when they immigrated from Germany. His great grandfather, also John Rosenow, had six sons and three of those became farmers, including his grandfather, Louis. Incidentally, another son became a doctor and joined the original Mayo Brothers in Rochester, Minnesota as a researcher. The three sons farmed next to one another, and their sons took over their respective farms. John’s father, Jacob, took over the original homestead farm, and eventually purchased one of his cousin’s adjacent properties as well.