EXHIBIT 5.1

                BARACK FERRAZZANO KIRSCHBAUM PERLMAN & NAGELBERG
                        333 WEST WACKER DRIVE, SUITE 2700
                             CHICAGO, ILLINOIS 60606
                            Telephone (312) 984-3100
                            Facsimile (312) 984-3150



                                  June 6, 2001



Landmark Merger Company
800 Poyntz Avenue
Manhattan, Kansas 66502

Ladies and Gentlemen:

         We have acted as special counsel to Landmark Merger Company, a Delaware
corporation (the "Company"), in connection with the merger of Landmark
Bancshares, Inc. ("Landmark") and MNB Bancshares, Inc. ("MNB") with and into the
Company, as described in the Form S-4 Registration Statement filed with the
Securities and Exchange Commission (the "SEC") on June 4, 2001 (together with
all amendments thereto, the "Registration Statement"). Capitalized terms used,
but not defined, herein shall have the meanings given such terms in the
Registration Statement. You have requested our opinion concerning certain
matters in connection with the Registration Statement.

         We have made such legal and factual investigation as we deemed
necessary for purposes of this opinion. In our investigation, we have assumed
the genuineness of all signatures, the proper execution of all documents
submitted to us as originals, the conformity to the original documents of all
documents submitted to us as copies and the authenticity of the originals of
such copies.

         In arriving at the opinions expressed below, we have reviewed and
examined the following documents:

                  (a) the Certificate of Incorporation and Bylaws of the
Company;

                  (b) the Agreement and Plan of Merger by and among Landmark,
MNB and the Company, dated April 19, 2001 (the "Merger Agreement");

                  (c) the Registration Statement, including the proxy
statement-prospectus constituting a part thereof (the "Proxy
Statement-Prospectus"); and

                  (d) Resolutions of the Board of Directors of the Company
relating to the merger transaction.



BARACK FERRAZZANO KIRSCHBAUM PERLMAN & NAGELBERG

Landmark Merger Company
June 6, 2001
Page 2

                  We call your attention to the fact that we are qualified to
practice law in the State of Illinois and express no opinion concerning any law
other than the General Corporation Law of the State of Delaware and the laws of
the United States of America.

         Based upon the foregoing, but assuming no responsibility for the
accuracy or the completeness of the data supplied by the Company and subject to
the qualifications, assumptions and limitations set forth herein, it is our
opinion that:

                  (a) The Company is a corporation duly organized, validly
existing and in good standing under the laws of the State of Delaware.

                  (b) The shares of the Company's common stock, $0.01 par value
per share, to be issued to the stockholders of Landmark and MNB as a result of
the Merger, when issued by the Company pursuant to the Merger Agreement, in
connection with the Merger, will be legally issued, fully paid and
non-assessable shares of the Company; provided that the Merger has been
consummated in accordance with the terms and conditions contained in the
Registration Statement.

                  (c) Provided that the Merger has been consummated in
accordance with the terms of the Merger Agreement, the Merger will qualify as a
merger under the laws of the State of Delaware.

         We express no opinion with respect to any specific legal issues other
than those explicitly addressed herein. We assume no obligation to advise you of
any change in the foregoing subsequent to the date of this opinion (even though
the change may affect the legal conclusion stated in this opinion letter).

         We hereby consent to the use in the Proxy Statement-Prospectus which
forms a part of the Registration Statement of our name, the statements with
respect to us as appearing under the heading "Certain Opinions" in the Proxy
Statement-Prospectus and to the use of this opinion as an exhibit to the
Registration Statement.

                              Very truly yours,

                              /s/ Barack Ferrazzano Kirschbaum
                                       Perlman & Nagelberg

                              BARACK FERRAZZANO KIRSCHBAUM
                              PERLMAN & NAGELBERG