CHAPMAN AND CUTLER LLP
                             111 WEST MONROE STREET
                               CHICAGO, IL 60603


                               November 18, 2014


Securities and Exchange Commission
100 F Street, N.E.
Washington, D.C.  20549


          Re: Guggenheim Defined Portfolios, Series 1263 (the "Fund")
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Ladies and Gentlemen:

      Enclosed please find a copy of the Registration Statement on Form S-6 for
the registration under the Securities Act of 1933 of Units representing the
ownership of interests in the subject Fund. This Registration Statement is filed
on November 18, 2014, on behalf of Guggenheim Funds Distributors, LLC (the
"Sponsor").

      Inasmuch as the Fund is not yet operative, no filings have been required
under any of the acts administered by the Commission. Therefore, for purposes of
Securities Act Release No. 5196 there are no delinquencies to be reported or
other references to be made to filings under the 1934 Act.

      No notification of registration or Registration Statement under the
Investment Company Act of 1940 is currently being submitted to the Commission,
as the filings under the 1940 Act (File No. 811-03763) are intended to apply not
only to that series of the Fund, but to all "subsequent series" as well.

      The Fund is expected to be comprised of the following unit investment
trust: Global Secular Growth Portfolio, 2014 Series (the "Trust"). The Trust
will invest in a portfolio of equity securities. We ask that the Commission
review the Trust as a result of the staff of the Commission's request that the
first series of a strategy be reviewed.

      We are advised that the Sponsor proposes to deposit securities and to
activate the subject Fund on as soon as practicable after the effective date of
the Registration Statement.

      In the event that you may have any questions with regard hereto or if
there is any way which we can be of assistance, please do not hesitate to
telephone Eric F. Fess collect at (312) 845-3781 or Morrison C. Warren at (312)
845-3484.

                                                               Very truly yours,

                                                      /s/ Chapman and Cutler LLP
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                                                          CHAPMAN AND CUTLER LLP