Section 625 ILCS 5/1-173 - Resident(a) Every natural person who resides in this state shall be deemed a resident of this State.(b) In the case of a firm, copartnership or association, if the principal place of business of such firm, copartnership or association is located in the State of Illinois, then such firm, copartnership or association shall be deemed a resident of the State of Illinois.(c) In the case of a corporation, if the corporation was incorporated under the laws of the State of Illinois or if the principal place of business of such corporation is in the State of Illinois, then such corporation shall be deemed a resident of the State of Illinois.