Illinois is known as "The Prairie State" due to its vast expanses of prairies that once covered much of the state.

The nickname "The Prairie State" reflects Illinois' historical landscape, which was dominated by prairies before much of it was cultivated or developed. The prairies, with their tall grasses and wildflowers, were a defining feature of Illinois' natural environment and played a key role in the state's agricultural development. Today, remnants of Illinois' prairie can still be found in preserved areas, and the nickname serves as a reminder of the state's rich natural history and agricultural roots.