Terms Used In Illinois Compiled Statutes 20 ILCS 1805/1

     All able-bodied citizens of this State and all other able-bodied residents in this State who have declared their intention to become citizens of the United States, between the ages of 18 and 45, except such as are expressly exempted by the laws of the United States and the State of Illinois, shall be subject to military duty and designated as the Illinois State Militia.