 The American Fur Company came to dominate trading in the area around the Great Lakes, absorbing competitors in a monopoly.John Jacob Astor had a townhouse at 233 Broadway in Manhattan and a country estate, Hellgate, in Northern New York City.In 1822, Astor established the Robert Stuart House on Mackinac Island in Michigan as headquarters for the reorganized American Fur Company, making the island a metropolis of the fur trade.