The Detroit Iron Works brought ironmaking to Zug Island in 1901 with the commissioning of a blast furnace built in 1902. In 1904 the works was purchased by the M.A. Hanna Company of Cleveland, Ohio which built a second blast furnace in 1909. At this time the island's two furnaces were reportedly the largest of their kind in the world, producing pig iron for foundry companies. The plant expanded and became part of the Great Lakes Steel Corporation in late 1931, becoming a key component of a fully integrated steel mill and a division of the larger National Steel Corporation. A third blast furnace was added in early 1938 while the existing furnaces were rebuilt and enlarged.