Since John Deere, therefore the fortune, were made here in Wisconsin I would have expected closer than a Florida trip. Sigh!
Checked up. There is a John Deere mansion closer than Florida, but still not in Wisconsin. It seems that Red Cliff Manor, the John Deere Mansion, is in Moline, Illinois. Either my history is wrong or the factory was not the center of John Deere enterprises.
I certainly don't intend to argue with the internet. It is on there so it must be true.
All I really knew about the John Deere company is that they built their farm machinery in Milwaukee, Wisconsin. That's why I thought the "JD fortune" might have started in Wis.
https://en.wikipedia.org/wiki/John_Deere
Here is some John Deere History. I was not going back far enough. He did start in IL but not in Moline, IL that came a bit later.
Deering Harvester Company was started by Wm. Deering not John Deere. In time the Deering name was dropped and Harvester Company -- eventually International Harvester Co. -- grew from there. We currently have a IH tractor for seldom done field work.