Exhibit 5.1

                         [McGUIREWOODS LLP LETTERHEAD]

                               January 31, 2001

CSX Corporation
One James Center
901 East Cary Street
Richmond, Virginia 23219

Ladies and Gentlemen:

     We have advised CSX Corporation, a Virginia corporation (the "Company"), in
connection with the Registration Statement on Form S-3 (the "Registration
Statement") filed by the Company with the Securities and Exchange Commission for
the purpose of registering under the Securities Act of 1933, as amended (the
"Act"), the Company's debt securities, debt warrants, preferred stock, preferred
stock warrants, depositary shares, common stock and common stock warrants
(collectively, the "Securities"), from the sale of which the Company may receive
proceeds of up to $800,000,000, to be offered from time to time by the Company
on terms to be determined at the time of the offering. Terms used and not
defined herein shall have the meanings given to them in the Registration
Statement.

     We have examined such corporate records, certificates and other documents,
and reviewed such questions of law, as we have considered necessary or
appropriate for the purpose of this opinion.

     On the basis of such examination and review, we advise you that, in our
opinion, when the terms of any class or series of the Securities have been
authorized by appropriate action of the Company and have been issued and sold as
described in the Registration Statement, the prospectus, the applicable
prospectus supplement and any underwriting or similar sales or distribution
agreement and, with respect to the debt securities, when such debt securities
have been duly executed, authenticated and delivered in accordance with the
applicable indenture or supplemental indenture, then (i) the Securities will be
legally issued and, with respect to shares of preferred stock and common stock,
fully-paid and non-assessable and (ii) the debt securities will be validly
authorized and issued and binding obligations of the Company, enforceable
against the Company in accordance with their terms, subject to bankruptcy,
insolvency, fraudulent transfer, reorganization, moratorium and similar laws of
general applicability relating to or affecting creditors' rights and to general
equity principles.

     We hereby consent to the filing of this opinion as an exhibit to the
Registration Statement and to references to us under the heading "Legal
Opinions" in the Registration Statement. We do not admit by giving this consent
that we are in the category of persons whose consent is required under Section 7
of the Act.

                                    Very truly yours,

                                    /s/ McGuireWoods LLP