EXHIBIT 99.1

                            MERCANTILE BANCORP, INC.

                                 Revocable Proxy
                     For a Special Meeting of Shareholders
                                 March 19, 2002

      The undersigned shareholder of Mercantile Bancorp, Inc. ("Mercantile")
 hereby appoints the Mercantile board of directors with the full power of
substitution, as attorneys and proxies, to represent and to vote, upon the
matters set forth in the Notice of the Special Meeting, the Proxy Statement-
Prospectus, and on their discretion, upon such other matters as may properly
come before the Special Meeting, all of the shares of Mercantile common stock
held of record by the undersigned on ______________, 2002, at the Special
Meeting to be held at 6:00 p.m., Central Time on March 19, 2002, at its
corporate headquarters, 8144 Walnut Hill Lane, #180, Dallas, Texas 75231, and at
any adjournment thereof. The undesigned hereby acknowledges receipt of the
accompanying Notice of the Special Meeting and Proxy Statement-Prospectus.

      This proxy, when properly executed and returned to Mercantile, will be
voted on the proposals set forth in the Notice of Special Meeting and the Proxy
Statement-Prospectus as directed on this card and in the discretion of the
proxies designated by the Mercantile board of directors as to any other business
that may come properly before the Special Meeting. If no vote is specified, said
proxies will vote in favor of the following proposals.

1.    FOR ___ OR AGAINST ___ OR ABSTAIN FROM VOTING ON ____ the authorization,
      adoption and approval of the Agreement and Plan of Merger dated as of
      November 29, 2001 between Mercantile and The Colonial BancGroup, Inc.

2.    FOR ___ OR AGAINST ___ OR ABSTAIN FROM VOTING ON ____ the approval of the
      proposal to approve certain proposed payments to Roy J. Salley, Chief
      Executive Officer or Mercantile and First Mercantile Bank, N. A., to the
      extent that such payments may constitute "parachute payments" within the
      meaning of section 280G of the Internal Revenue Code.


PLEASE MARK, SIGN BELOW, DATE, AND RETURN THIS PROXY CARD PROMPTLY IN THE
ENVELOPE FURNISHED.

                                   Please sign exactly as name appears on this
                                   Proxy Card. When shares are held by joint
                                   tenants, both should sign. When signing as
                                   attorney, executor, administrator, trustee,
                                   or guardian, please give full title as such.
                                   If a corporation, please sign in full
                                   corporate name by president or other
                                   authorized officer. If a partnership, please
                                   sign in partnership name by authorized
                                   person.

                                   DATED:  ____________________ 2002

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                                   Signature

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                                   Signature (if held jointly)