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                   SECURITIES AND EXCHANGE COMMISSION
                         WASHINGTON, D.C. 20549

                              FORM 10-K/A

       AMENDMENT NO. 1 TO ANNUAL REPORT PURSUANT TO SECTION 13 OF
                   THE SECURITIES EXCHANGE ACT OF 1934

 FOR THE FISCAL YEAR ENDED DECEMBER 31, 1998     COMMISSION FILE NO. 1-11792

                      MERCANTILE BANCORPORATION INC.
          (EXACT NAME OF REGISTRANT AS SPECIFIED IN ITS CHARTER)

                    MISSOURI                       43-0951744
            (STATE OF INCORPORATION)             (IRS EMPLOYER
                                              IDENTIFICATION NO.)

                  P.O. BOX 524                    63166-0524
              ST. LOUIS, MISSOURI                 (ZIP CODE)
   (ADDRESS OF PRINCIPAL EXECUTIVE OFFICES)

REGISTRANT'S TELEPHONE NUMBER, INCLUDING AREA CODE: 314-418-2525

SECURITIES REGISTERED PURSUANT TO        NAME OF EXCHANGE ON WHICH REGISTERED:
 SECTION 12(b) OF THE ACT:
   (1) COMMON STOCK ($0.01 PAR VALUE)    (1) NEW YORK STOCK EXCHANGE
   (2) PREFERRED STOCK PURCHASE RIGHTS   (2) NEW YORK STOCK EXCHANGE

SECURITIES REGISTERED PURSUANT TO SECTION 12(g) OF THE ACT:  None

INDICATE BY CHECK MARK WHETHER THE REGISTRANT (1) HAS FILED ALL REPORTS
REQUIRED TO BE FILED BY SECTION 13 OF THE SECURITIES EXCHANGE ACT OF 1934
DURING THE PRECEDING 12 MONTHS, AND (2) HAS BEEN SUBJECT TO SUCH FILING
REQUIREMENTS FOR THE PAST 90 DAYS.  YES  X   NO
                                        ---     ---

INDICATE BY CHECK MARK IF DISCLOSURE OF DELINQUENT FILERS PURSUANT TO ITEM 405
OF REGULATION S-K IS NOT CONTAINED HEREIN, AND WILL NOT BE CONTAINED, TO THE
BEST OF REGISTRANT'S KNOWLEDGE, IN DEFINITIVE PROXY OR INFORMATION STATEMENTS
INCORPORATED BY REFERENCE IN PART III OF THIS FORM 10-K. [X]

STATE THE AGGREGATE MARKET VALUE OF THE VOTING STOCK HELD BY NON-AFFILIATES OF
THE REGISTRANT AS OF  JUNE 17, 1999:
COMMON STOCK, $0.01 PAR VALUE, $7,524,087,509.

INDICATE THE NUMBER OF SHARES OUTSTANDING OF EACH OF THE REGISTRANT'S CLASSES
OF COMMON STOCK, AS OF JUNE 17, 1999:
COMMON STOCK $0.01 PAR VALUE, 158,156,398 SHARES OUTSTANDING.

                   DOCUMENTS INCORPORATED BY REFERENCE

THE FOLLOWING DOCUMENTS ARE INCORPORATED BY REFERENCE:  NOT APPLICABLE.

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The "Exhibit Index" as previously filed with the Form 10-K is hereby amended
by inserting the following entries:

      No. 2-1     Agreement and Plan of Merger by and between Mercantile
                  Bancorporation Inc. and Firstar Corporation dated as
                  of April 30, 1999.<F**>

      No. 23-2    Consent of KPMG LLP (relating to report dated June 23,
                  1999, Mercantile Bancorporation Inc. Horizon
                  Investment and Savings Plan and Trust Financial
                  Statements).<F*>

      No. 99-1    Report of the Independent Auditors KPMG LLP dated June
                  23, 1999; Statements of Net Assets Available for Plan
                  Benefits of Mercantile Bancorporation Inc. Horizon
                  Investment and Savings Plan and Trust as of December
                  31, 1998 and 1997; Statements of Changes in Net Assets
                  Available For Plan Benefits for the years then ended;
                  and the Notes and Schedules thereto.<F*>

      No. 99-2    Stock Option Agreement, dated April 30, 1999, between
                  Firstar Corporation, a Wisconsin corporation
                  ("Issuer"), and Mercantile Bancorporation Inc., a
                  Missouri corporation ("Grantee").<F**>

      No. 99-3    Stock Option Agreement, dated April 30, 1999, between
                  Mercantile Bancorporation Inc., a Missouri corporation
                  ("Issuer"), and Firstar Corporation, a Wisconsin
                  Corporation ("Grantee").<F**>

[FN]
<F*>  Filed herewith.
<F**> Filed with the Registrant's Quarterly Report on Form 10-Q for the
      quarter ended March 31, 1999 dated May 14, 1999.


                              
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                              SIGNATURES

     Pursuant to the requirements of the Securities Exchange Act of 1934,
the Registrant has duly caused this amendment to be signed on its behalf by
the undersigned, thereunto duly authorized.




                                  MERCANTILE BANCORPORATION INC.
                                  (Registrant)



Date: June 29, 1999               By: /s/ John W. McClure
                                      ---------------------------
                                      John W. McClure
                                      Vice Chairman and Chief
                                        Financial Officer


                              
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                          EXHIBIT INDEX


     EXHIBIT NO.                    DESCRIPTION

      No. 2-1        Agreement and Plan of Merger by and between
                     Mercantile Bancorporation Inc. and Firstar
                     Corporation dated as of April 30, 1999, as filed
                     as Exhibit 2 to the Registrant's Quarterly Report
                     on Form 10-Q for the quarter ended March 31, 1999,
                     is incorporated herein by reference.

      No. 3-1(a)     Restated Articles of Incorporation of the
                     Registrant, as amended and currently in effect,
                     filed as Exhibit 3 to Registrant's Quarterly Report
                     on Form 10-Q for the quarter ended March 31, 1997,
                     are incorporated herein by reference.

      No. 3-1(b)     Certificate of Designation, Preferences and Rights
                     of Series B Junior Participating Preferred Stock of
                     the Registrant filed as Exhibit 3-1(b) to
                     Registrant's Quarterly Report on Form 10-Q for the
                     quarter ended June 30, 1998 (Commission File No.
                     1-11792), is incorporated herein by reference.

      No. 3-2        By-Laws of the Registrant, as amended and currently
                     in effect, filed as Exhibit 3.2 to Amendment No. 2
                     to Registrant's Registration Statement on Form 4
                     (No. 333-17757), are incorporated herein by
                     reference.

      No. 4-1        Form of Indenture Regarding Subordinated Securities
                     between the Registrant and The First National Bank
                     of Chicago as Trustee, filed on March 31, 1992 as
                     Exhibit 4.1 to Registrant's Report on Form 8-K
                     dated September 24, 1992 (Commission File No.
                     1-11792), is incorporated herein by reference.

      No. 4-2        Rights Agreement dated as of May 20, 1998, between
                     Registrant and Harris Trust and Savings Bank, as
                     Rights Agent (including as an exhibit thereto the
                     form of Rights Certificate) filed as Exhibit 4-2 to
                     the Registrant's Quarterly Report on Form 10-Q for
                     the quarter ended June 30, 1998 (Commission File
                     No. 1-11792), is incorporated herein by
                     reference.

      No. 4-3        Form of Indenture Regarding Senior Debt Securities,
                     filed as Exhibit 4.1 to Registrant's Registration
                     Statement on Form S-3 (No. 333-25775), is
                     incorporated herein by reference.

      No. 4-4        Form of Indenture Regarding Subordinated Debt
                     Securities, filed as Exhibit 4.2 to Registrant's
                     Registration Statement on Form S-3 (No. 333-25775),
                     is incorporated herein by reference.

      No. 4-5        Indenture, dated February 4, 1997; First
                     Supplemental Indenture, dated February 4, 1997, and
                     Supplemental Indenture of First Supplemental
                     Indenture, dated May 22, 1997, between the Company,
                     as issuer, and The Chase Manhattan Bank, as
                     Indenture Trustee, filed as Exhibits 4.5, 4.6 and
                     4.12, respectively, to the Company's Registration
                     Statement on Form S-4 (No. 333-25131), are
                     incorporated herein by reference.

      No. 10-1       The Mercantile Bancorporation Inc. 1987 Stock
                     Option Plan, as amended, filed as Exhibit 10-3 to
                     Registrant's Annual Report on Form 10-K for the
                     year ended December 31, 1989 (Commission File No.
                     1-11792), is incorporated herein by
                     reference. <F+>




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      No. 10-2       The Mercantile Bancorporation Inc. Amended and
                     Restated Executive Incentive Compensation Plan,
                     filed as Annex H to Registrant's definitive Proxy
                     Statement for the 1997 Annual Meeting of
                     Shareholders, is incorporated herein by
                     reference. <F+>

      No. 10-3       The Mercantile Bancorporation Inc. Employee Stock
                     Purchase Plan, filed as Exhibit 10-7 to Registrant's
                     Annual Report on Form 10-K for the year ended December
                     31, 1989 (Commission File No. 1-11792), is
                     incorporated herein by reference. <F+>

      No. 10-4       The Mercantile Bancorporation Inc. 1991 Employee
                     Incentive Plan, filed as Exhibit 10-7 to Registrant's
                     Annual Report on Form 10-K for the year ended December
                     31, 1990 (Commission File No. 1-11792), is
                     incorporated herein by reference. <F+>

      No. 10-5       Amendment Number One to the Mercantile Bancorporation
                     Inc. 1991 Employee Incentive Plan, filed as Exhibit
                     10-6 to Registrant's Report on Form 10-K for the year
                     ended December 31, 1994 (Commission File No. 1-11792),
                     is incorporated herein by reference. <F+>

      No. 10-6       The Mercantile Bancorporation Inc. Amended and
                     Restated Stock Incentive Plan, filed as Annex G to
                     Registrant's definitive Proxy Statement for the 1997
                     Annual Meeting of Shareholders (Commission File No.
                     1-11792), is incorporated herein by reference. <F+>

      No. 10-7       The Mercantile Bancorporation Inc. 1994 Stock
                     Incentive Plan for Non-Employee Directors, filed as
                     Appendix E to Registrant's definitive Proxy Statement
                     for the 1994 Annual Meeting of Shareholders
                     (Commission File No. 1-11792), is incorporated herein
                     by reference. <F+>

      No. 10-8       The Mercantile Bancorporation Inc. Amended and
                     Restated Voluntary Deferred Compensation Plan, filed
                     as Exhibit 10.1 to Registrant's Registration Statement
                     on Form S-8 (File No. 333-47713), is incorporated
                     herein by reference. <F+>

      No. 10-9       Mercantile Bancorporation Inc. Supplemental Retirement
                     Plan, filed as Exhibit 10-12 to Registrant's Annual
                     Report on Form 10-K for the year ended December 31,
                     1992 (Commission File No. 1-11792), is incorporated
                     herein by reference. <F+>

      No. 10-10      Mercantile Bancorporation Inc. Voluntary Deferred
                     Compensation Plan for Non-Employee Affiliate Directors
                     and Advisory Directors, filed as Exhibit 10.3 to
                     Registrant's Registration Statement on Form S-8 (File
                     No. 333-47713), is incorporated herein by reference. <F+>

      No. 10-11      Mercantile Bancorporation Inc. Amended and Restated
                     Stock Incentive Plan for Non-Employee Directors, filed
                     as Exhibit 10.2 to Registrant's Registration Statement
                     on Form S-8 (File No. 333-47713), is incorporated
                     herein by reference. <F+>

      No. 10-12      Employment Agreement for Thomas H. Jacobsen, as
                     amended and restated, filed as Exhibit 10.9 to
                     Registrant's Annual Report on Form 10-K for the year
                     ended December 31, 1997 (Commission File No. 1-11792),
                     is incorporated herein by reference. <F+>




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      No. 10-13      Form of Change of Control Employment Agreement for
                     John W. McClure, W. Randolph Adams, John Q. Arnold and
                     Certain Other Executive Officers, filed as Exhibit 10-
                     10 to Registrant's Report on Form 10-K for the year
                     ended December 31, 1989 (Commission File No. 1-11792),
                     is incorporated herein by reference. <F+>

      No. 10-14      Employment Agreement for Alvin J. Siteman, dated
                     November 18, 1996, filed as Exhibit 10.3 to
                     Registrant's Report on Form 10-Q for the quarter ended
                     March 31, 1997 (Commission File No. 1-11792), is
                     incorporated herein by reference. <F+>

      No. 10-15      Employment Agreement for John P. Dubinsky, dated
                     October 27, 1996, filed as Exhibit 10.4 to
                     Registrant's Report on Form 10-Q for the quarter ended
                     March 31, 1997 (Commission File No. 1-11792), is
                     incorporated herein by reference. <F+>

      No. 13         Excerpts from Annual Report of the Registrant to its
                     Shareholders for the year ended December 31, 1998. <F*>

      No. 21         Subsidiaries of the Registrant as of February 26,
                     1998. <F*>

      No. 23-1       Consent of KPMG LLP. <F*>

      No. 23-2       Consent of KPMG LLP (relating to report dated June 23,
                     1999, Mercantile Bancorporation Inc. Horizon
                     Investment and Savings Plan and Trust Financial
                     Statements.)

      No. 24         Power of Attorney (on signature page). <F*>

      No. 27         Financial Data Schedule. <F*>

      No. 99-1       Report of the Independent Auditors KPMG LLP dated June
                     23, 1999; Statements of Net Assets Available for Plan
                     Benefits of Mercantile Bancorporation Inc. Horizon
                     Investment and Savings Plan and Trust as of December
                     31, 1998 and 1997; Statements of Changes in Net Assets
                     Available For Plan Benefits for the years then ended;
                     and the Notes and Schedules thereto.

      No. 99-2       Stock Option Agreement, dated April 30, 1999, between
                     Firstar Corporation, a Wisconsin corporation
                     ("Issuer") and Mercantile Bancorporation Inc., a
                     Missouri corporation ("Grantee"), as filed as Exhibit 99.1
                     to the Registrant's Quarterly Report on Form 10-Q for the
                     quarter ended March 31, 1999, is incorporated herein by
                     reference.

      No. 99-3       Stock Option Agreement, dated April 30, 1999, between
                     Mercantile Bancorporation Inc., a Missouri corporation
                     ("Issuer"), and Firstar Corporation, a Wisconsin
                     Corporation ("Grantee"), as filed as Exhibit 99.2 to the
                     Registrant's Quarterly Report on Form 10-Q for the quarter
                     ended March 31, 1999, is incorporated herein by reference.
[FN]
<F*> Filed with the Registrant's Annual Report on Form 10-K for the year
     ended December 31, 1998.

<F+> Management contract or compensatory plan or arrangement.