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                                                                     EXHIBIT 5.1
                               September 30, 1998

US Xchange, L.L.C.
20 Monroe Avenue NW, Suite 450
Grand Rapids, Michigan 49503

Ladies and Gentlemen:

          We are acting as special counsel for US Xchange, L.L.C., a Michigan
limited liability company (the "Company") in connection with various legal
matters relating to the filing with the Securities and Exchange Commission of a
Registration Statement on Form S-4 (the "Registration Statement") under the
Securities Act of 1933, as amended (the "Securities Act"), covering an offer to
exchange (the "Exchange Offer") $1,000 principal amount of the Company's 15%
Senior Notes due July 1, 2008 (the "Exchange Notes") for each $1,000 principal
amount of its outstanding 15% Senior Notes due July 1, 2008 (the "Private
Notes"), of which $200,000,000 aggregate principal amount is outstanding on the
date hereof. The Exchange Notes are to be issued pursuant to an Indenture, dated
as of June 25, 1998 (the "Indenture"), between the Company and The Bank of New
York, as Trustee, which is filed as an exhibit to the Registration Statement.

          In connection herewith, we have examined and relied without
independent investigation as to matters of fact upon such certificates of public
officials, such statements and certificates of officers of the Company, 
originals or copies certified to our satisfaction of the Registration Statement,
the Indenture, the Exchange Notes, the Registration Rights Agreement, dated as
of June 25, 1998, between the Company and Morgan Stanley & Co. Incorporated, the
Articles of Organization of the Company and the Operating Agreement dated as of
August 1, 1996 of the Company, proceedings of the Members of the Company and
such other Company records, documents, certificates and instruments as we have
deemed necessary or appropriate in order to enable us to render the opinions
expressed below. In rendering this opinion, we have assumed the genuineness of
all signatures on all documents examined by us, the authenticity of all
documents submitted to us as originals and the conformity to authentic originals
of all documents submitted to us as certified or photostatted copies. 

          We express no opinion as to the applicability or effect of (i) any
bankruptcy, insolvency, reorganization, moratorium and other similar laws
relating to or affecting creditors' rights generally, or (ii) general principles
of equity, including, without limitation, concepts of reasonableness,
materiality, good faith and fair dealing and the possible unavailability of
specific performance, injunctive relief or other equitable remedies, regardless
of whether enforceability is considered in a proceeding in equity or at law.

          Based upon the foregoing and in reliance thereon and subject to the
qualifications and limitations stated herein, we are of the opinion that:

          (1)  The Company is a limited liability company validly existing in
               good standing under the laws of the state of Michigan; and

          (2)  When,

               (i)   the Registration Statement, including any amendments
                     thereto, shall have become effective under the Securities
                     Act;

               (ii)  the Indenture has been duly qualified under the Trust
                     Indenture Act of 1939, as amended; and

               (iii) the Exchange Notes shall have been duly executed and
                     authenticated in accordance with the provisions of the
                     Indenture and duly delivered to the holders thereof in
                     exchange for the Private Notes;

                     then the Exchange Notes will be valid and binding
                     obligations of the Company.

 
 
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US Xchange, L.L.C.
September 30, 1998
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     In addition, based on the assumptions and subject to the qualifications set
forth therein, our opinion as to the material United States federal income tax
consequences of the Exchange Offer is set forth in the Prospectus included as
part of the Registration Statement (the "Prospectus") under the caption "Certain
United States Federal Income Tax Considerations" and we hereby confirm such
opinion as set forth therein.

     In rendering the opinion expressed in the immediately preceding paragraph,
we have considered the applicable provisions of the Internal Revenue Code of
1986, as amended (the "Code"), applicable final, temporary and proposed
Treasury Regulations promulgated thereunder by the United States Treasury
Department (the "Regulations"), pertinent judicial authorities, rulings of the
Internal Revenue Service and such other authorities as we have considered
relevant. It should be noted that the Code, the Regulations and such judicial
decisions, administrative interpretations and authorities are subject to change
at any time and, in some circumstances, with retroactive effect.  We have also
assumed that the Registration Statement reflects all of the material facts, and
our opinion is expressly conditioned on, among other things, the accuracy of
all such facts as of the date hereof, and the continuing accuracy of all such
facts through and as of the expiration date of the Exchange Offer. Any
variation or difference in the facts referred to, set forth or assumed herein
or in the Registration Statement or in any of the authorities upon which our
opinion is based could affect our opinion.

     This opinion is not rendered with respect to any laws other than the
Michigan Limited Liability Company Act as reported in Prentice-Hall Information
Services Corporation Statutes, as supplemented through May 1, 1998, and the
federal laws of the United States.

     We hereby consent to (i) the filing of this opinion as an exhibit to the
Registration Statement, (ii) the description of our opinion under the caption
"Certain United States Federal Income Tax Considerations" in the Prospectus and
(iii) the reference to our firm under the captions "Certain United States
Federal Income Tax Considerations" and "Validity of the Exchange Notes" in the
Prospectus.  We also consent to your filing copies of this opinion as an exhibit
to the Registration Statement with agencies of such states as you deem necessary
in the course of complying with the laws of such states regarding the Exchange
Offer.  In giving this consent, we do not admit that we are in the category of
persons whose consent is required under Section 7 of the Securities Act or the
rules and regulations of the Securities and Exchange Commission thereunder.

                             Very truly yours,

                             /s/ Bryan Cave LLP

                             Bryan Cave LLP