The first Dairy Queen store opened in Joliet, Illinois, in 1940.
The store introduced soft serve developed through the work of John Fremont McCullough and his son Alex. Their product was tested in Illinois before the first permanent Dairy Queen location opened. The name referred to the idea that the soft-serve product was treated as the leading item, or “queen,” of dairy foods.
Dairy Queen expanded through franchising rather than relying only on company-operated stores. Its menu later grew beyond soft serve to include frozen treats, burgers, chicken, and other quick-service foods. The brand became especially associated with Blizzards, but that product arrived decades after the original store opened.
Minneapolis and St. Paul are sometimes linked to Dairy Queen because the company developed its corporate operations in Minnesota. Chicago is also nearby and is a major Illinois city, but neither city was the location of the first Dairy Queen store. That landmark was in Joliet.