EXHIBIT 15

May 4, 2004

USG Corporation
125 South Franklin Street
Chicago, Illinois  60606

We have made a review, in accordance with standards established by the American
Institute of Certified Public Accountants, of the unaudited interim financial
information of USG Corporation and subsidiaries for the period ended March 31,
2004, as indicated in our report dated April 28, 2004; because we did not
perform an audit, we expressed no opinion on that information.

We are aware that our report referred to above, which is included in your
Quarterly Report on Form 10-Q for the quarter ended March 31, 2003, is
incorporated by reference in Registration Statement Nos. 33-40136, 33-64217, and
33-60563 (as amended) on Form S-3, Registration Statement Nos. 33-22581 (as
amended), 33-22930, 33-36303, 33-52715, 33-63554, and 33-65383 on Form S-8, and
Registration Statement Nos. 33-52573 on Form S-1.

We also are aware that the aforementioned report, pursuant to Rule 436(c) under
the Securities Act of 1933, is not considered a part of the Registration
Statements prepared or certified by an accountant or a report prepared or
certified by an accountant within the meaning of Sections 7 and 11 of that Act.

/s/ DELOITTE & TOUCHE LLP

DELOITTE & TOUCHE LLP

Chicago, Illinois

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