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                                                                   Exhibit 10.54



                                                               February 28, 2000
Mr. William Mounger, II
c/o Tritel, Inc.
111 East Capitol Street, Suite 500
Jackson, Mississippi  39201


Dear Mr. Mounger:

     Reference is made to that certain agreement and plan of reorganization and
contribution by and among TeleCorp PCS, Inc. ("TeleCorp"), Tritel, Inc.
("Tritel") and AT&T Wireless Services, Inc., dated as of February 28, 2000 (the
"Reorganization Agreement").  Capitalized words and phrases used and not defined
herein shall have the meanings ascribed to them in the Reorganization Agreement.

     At any time after the first anniversary of the Closing, you shall be
entitled to require Tritel (the "Put Right"), and the Holding Company shall be
obligated, to purchase your shares of Voting Preference Stock for $10,000,000 in
immediately available funds payable within five business days written notice of
your election to exercise the Put Right upon the contemporaneous surrender of
the certificates representing your shares of Voting Preference Stock endorsed in
blank.  In the event that either Thomas Sullivan or Gerald Vento, separately or
together, in one or a series of transactions, shall engage in a Control Transfer
Transaction (as herein defined), and you have not theretofor exercised the Put
Right, you shall be deemed to have exercised the Put Right and shall be entitled
to receive from Tritel an amount equal to the sum of (A) $10,000,000 and (B) 50%
of the sum of (i) the amount by which the consideration received by Thomas
Sullivan in the Control Transfer Transaction exceeds $10,000,000 and (ii) the
amount by which the consideration received by Gerald Vento in the Control
Transfer Transaction exceeds $10,000,000 (the sum of the amounts specified in
(A) and (B) being the "Control Transaction Amount").  In the event that either
Thomas Sullivan or Gerald Vento, separately or together, in one or a series of
transactions, shall engage in a Control Transfer Transaction and you had
previously exercised the Put Right and received $10,000,000 therefor, you shall
be entitled to receive from Tritel an amount, which shall also constitute a
Control Transaction Amount, equal to 50% of the sum of (i) the amount by which
the consideration received by Thomas Sullivan in the Control Transfer
Transaction exceeds the sum of (x) $10,000,000 and (y) interest on $10,000,000
calculated from the date payment was received upon exercise of the Put Right
(the "Put Payment Date") through the effective date of the Control Transfer
Transaction calculated at the yield reported by The Wall Street Journal for 30-
day United States Government Treasury
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Securities on the Put Payment Date (the "Applicable Rate") and (ii) the amount
by which the consideration received by Gerald Vento in the Control Transfer
Transaction exceeds the sum of (w) $10,000,000 and (z) interest on $10,000,000
calculated from the Put Payment Date through the effective date of the Control
Transfer Transaction calculated at the Applicable Rate. Consideration in a
Control Transfer Transaction shall include cash, securities, licenses and other
intangible rights, forgiveness of indebtedness and any payments to third parties
for the benefit of Thomas Sullivan or Gerald Vento; it being understood that
consideration received by either Thomas Sullivan or Gerald Vento for shares of
Holding Company Capital Stock other than Voting Preference Stock sold by them to
a third party contemporaneously with a Control Transfer Transaction shall not be
attributed to consideration received in the Control Transfer Transaction. In the
event any portion of the consideration directly or indirectly received by Thomas
Sullivan or Gerald Vento in the Control Transfer Transaction consists of
securities, assets or intangible rights, such portion of the consideration shall
be valued at the fair market value thereof as of the effective date of the
Control Transfer Transaction. Tritel shall provide you with notice that an
agreement involving a Control Transfer Transaction has been entered into by
itself and/or either or both of Thomas Sullivan and Gerald Vento promptly after
it becomes aware of such agreement and Tritel shall, or in the event Tritel is
not a party to the Agreement, Thomas Sullivan and/or Gerald Vento shall deliver
to you fully executed copies of such agreement(s) within two Business Days of
the date of such agreement(s). Tritel shall pay the Control Transaction Amount
in immediately available funds on the date on which the Control Transfer
Transaction becomes effective.

     Neither the Holding Company nor any of its subsidiaries shall claim on any
income tax return a deduction for any amounts payable under this letter
agreement except to the extent a court of competent jurisdiction reaches a final
determination, or you agree with any relevant taxing authority, that any such
amounts constitute compensation to you.

     TeleCorp and Tritel shall cause the Holding Company to execute an
acknowledgement of Tritel's obligations under this Agreement and the Holding
Company's obligation under the immediately preceding paragraph reasonably
satisfactory to you no later than the Closing under the Reorganization
Agreement.

     As used herein, a "Control Transfer Transaction" means any one or a series
of transactions as a result of which the voting power of Voting Preference Stock
representing in excess of 50% of the voting power of all then outstanding shares
of Holding Company Capital Stock entitled to vote generally in the election of
directors is directly or indirectly sold, transferred, assigned, exchanged and
converted including, without limitation, (i) by a sale, transfer or exchange of
the record or beneficial ownership of Voting Preference Stock, (ii) by any
merger, consolidation, recapitalization or restructuring involving the Holding
Company, (iii) by the execution and delivery of a voting, trust or custody
agreement or the deposit of Voting Preference Stock into a trust or similar
arrangement or (iv) through any other arrangement or understanding as a result
of which a third party acquires the power to vote such Voting Preference Stock,
irrespective of whether record or beneficial ownership has been transferred.

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     All notices and other communications which are required or may be given
under this letter agreement shall be in writing and shall be deemed to have been
duly given if delivered personally, if telecopied or mailed, first class mail,
postage prepaid, return receipt requested, or by overnight courier as follows:

     If to Tritel:                  Tritel, Inc.
                                    111 East Capitol Street, Suite 500
                                    Jackson, Mississippi  39201


     If to William Mounger:     c/o Tritel, Inc.
                                    111 East Capitol Street, Suite 500
                                    Jackson, Mississippi  39201

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     Kindly acknowledge your agreement to the foregoing by executing this letter
where indicated below, whereupon this letter agreement shall constitute a valid
and binding agreement of the parties hereto.

                                              Very truly yours,

                                              TELECORP PCS, INC.

                                              By_________________________

                                              Name:
                                              Title:

                                              TRITEL, INC.

                                              By_________________________

                                              Name:
                                              Title:


Agreed to as of the date first written        With respect to the sixth sentence
above                                         of the second paragraph only:




_______________________________________       ________________________
William Mounger, II                           Thomas Sullivan


                                              ________________________
                                              Gerald Vento

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