EXHIBIT 1 January 25, 1995 Board of Directors FirstRock Bancorp, Inc. 612 North Main Street Rockford, Illinois 61103 Members of the Board: You have requested our opinion as to the fairness of the merger consideration (the "Merger Consideration"), from a financial point of view, to the shareholders of FirstRock Bancorp, Inc. ("FirstRock") with respect to the proposed merger of FirstRock with and into First Financial Corporation ("First Financial"). FirstRock has entered into an Agreement and Plan of Reorganization and a related Agreement and Plan of Merger (collectively the "Agreements"), both dated October 26, 1994, between First Financial and FirstRock. As is set forth in the Agreements, each outstanding share of common stock of FirstRock will be converted into and be exchangeable for the number of shares of Common Stock, $1.00 par value per share, of First Financial equal to a fraction, the numerator of which shall be equal to $27.10 and the denominator of which shall be equal to the average closing price per share of Common Stock of First Financial as reported on the Nasdaq Stock Market for the fifteen trading days ending on the fourth trading day prior to the Effective Date of the Merger. During the course of our engagement, we have, among other things: 1) reviewed the Agreements, the audited financial statements of FirstRock and First Financial for the most recent three fiscal years, and unaudited financial statements through September 30, 1994 as reported on Form 10-Q, Office of Thrift Supervision ("OTS") Thrift Financial Reports of FirstRock, as well as other internally generated FirstRock reports relating to asset/liability management, asset quality and so forth; 2) reviewed and analyzed other material bearing upon the financial and operating condition of First Financial and FirstRock and material prepared in connection with the proposed transaction; 3) reviewed the operating characteristics of certain other financial institutions deemed relevant to the contemplated transaction; 4) reviewed the nature and terms of recent sale and merger transactions involving banks, thrifts, bank and thrift holding companies and other financial institutions that we consider relevant; January 25, 1995 Board of Directors FirstRock Bancorp, Inc. Page -2- 5) reviewed historical and current market data for First Financial and FirstRock common stock; 6) reviewed financial and other information provided to us by the managements' of First Financial and FirstRock; 7) conducted meetings with members of the senior management of First Financial and FirstRock for the purpose of reviewing the future prospects of First Financial and FirstRock; 8) reviewed certain information including forecasts pertaining to prospective cost savings and revenue enhancements relative to the proposed transactions; 9) evaluated the proforma ownership of First Financial common stock by FirstRock shareholders, relative to the proforma condition of FirstRock's assets, liabilities, equity and earnings to the proforma company. The Chicago Corporation, as part of its investment banking business, is continually engaged in the valuation of banks and bank holding companies and thrifts and thrift holding companies in connection with mergers and acquisitions as well as initial and secondary offerings of securities as well as valuations for other purposes. The Chicago corporation is a member of all principal U.S. Securities exchanges and in the conduct of our broker-dealer activities may from time to time purchase securities from, and sell securities to, FirstRock and First Financial and as a market maker buy or sell the equity securities of FirstRock for our own account and for the accounts of customers. In rendering this fairness opinion we have acted exclusively on behalf of the Board of Directors of FirstRock and will receive a fee from FirstRock for our services. In rendering this opinion, we have relied upon, without independent verification, the accuracy and completeness of the financial and other information and representations provided to us by First Financial and FirstRock. We have relied upon the management of FirstRock and First Financial as to the reasonableness and achievability of the financial forecasts and projections (and the assumptions and basis therefore) provided to us, and have assumed that such forecasts and projections are the best available estimates of management. Based on the foregoing and our experience as investment bankers, we are of the opinion that, as of the date hereof, the Merger Consideration to be paid to the shareholders of FirstRock as described in the Agreements, is fair from a financial point of view. Sincerely, - ---------------------------- /s/The Chicago Corporation THE CHICAGO CORPORATION