Christened as the "Detroit" in 1922 by the Defoe Boat & Motor Works in Bay City, MI, the Vessel spent her early years operating out of its namesake city. In 1936 the Detroit was purchased by Leonard A. Seeberger, a ferry operator on Madeline Island in the Apostle Islands. During the Word War II era, the Detroit's home port was Duluth, MN and she operated on Lake Superior as a pickup vessel for the H. Christiansen & Sons Fish Company.

In the 1950’s the famous Arnold Transit Company purchased the Detroit for use as a ferry in the Straights of Mackinaw. She was renamed the "Iroquois" upon joining her fleet mates, the Ottawa and the Chippewa. In 1962 Captain Art Fransee brought the Iroquois to her present home in Milwaukee to operate as a tour boat. In 1981 Captain Roger Chapman purchased the Iroquois. Over the next 25 years Captain Chapman turned the Iroquois into one of the most recognizable attractions on Milwaukee’s waterways.

Originally The Iroquois was powered by a 60 hp Fairbanks-Morse engine. In 1947 she was upgraded with a 120 hp Kahlenberg four-cylinder, direct reversing, diesel engine. Built in Two Rivers, WI, this cast iron power plant was over 13 feet long and had a massive dry weight of nearly 12,000 pounds! After a main bearing failure, the Kahlenberg was replaced in 1998 by a modern Detroit Diesel marine engine.