205 ILCS 5/24
The executed merger agreement together with copies of the resolutions of the stockholders of each merging bank or insured savings association approving it, certified by the bank's or insured savings association's president or vice-president or the cashier, shall be filed with the Commissioner. A merger that is to result in a State bank shall, unless a later date is specified in the agreement, become effective when the Commissioner has approved the agreement and issued a certificate of merger to the continuing bank. The charters of the merging banks or insured savings association, other than the continuing bank, shall thereupon automatically terminate. If, after May 31, 1997, the merger will result in an out-of-state bank, the charter of a merging State bank shall terminate upon notice to the Commissioner that the merger is effective. The certificate of merger shall specify the name of each merging bank or insured savings association and the name of the continuing bank, and the amendments to the charter of the continuing bank provided for by the merger agreement. The certificate shall be conclusive evidence of the merger and of the correctness of all proceedings therefor in all courts and places.
205 ILCS 5/24