Outside the walls of the fort, early nineteenth century life in Prairie du Chien was still dominated by the fur trade. Prairie du Chien's most well-known traders during this time were Michel Brisbois, Joseph Rolette, Nathan Myrick, and Hercules L. Dousman. Dousman built a fortune in the fur trade, which, combined with income from investments in land, steamboats, and railroads, propelled him to become the first millionaire in Wisconsin. Dousman died in 1868, and his son, H. Louis Dousman, inherited much of his fortune. In 1870 Louis Dousman used his inheritance to construct a luxurious Victorian mansion over the site of the former Fort Shelby. When Louis died unexpectedly in 1886, his family renamed the home "Villa Louis" in his memory. The Dousman family continued to occupy the home until 1913. Nearly 40 years later, in 1952, the mansion became Wisconsin's first state-operated historic site.