Symphony No. 2 - Brahms
Johannes Brahms (1833-1897), was a German composer of the Romantic era who used trombones sparingly but strategically.
Brahms completed Symphony No. 2 in 1877. Brahms uses the trombone section with great care in this symphony in both quiet passages and in the dramatic final moments, where the trombones have a magnificent exposed D major chord all to themselves in the final five measures.
To learn more about the composer, visit Johannes Brahms on Wikipedia.
For more on the composition, visit Brahms Symphony No. 2 on Wikipedia.
Performance
Brahms - Symphony No.2 (Karajan, 1986)
Excerpts
Brahms Symphony No. 2 audio excerpts are available on tromboneexcerpts.org.
Trombone Parts and Full Score
The full score of Symphony No. 2 is available on IMSLP.org.
NOTE: IMSLP provides access to public-domain scores and parts, with copyright status varying by country. Users are responsible for observing applicable copyright laws.
Trombone parts are available on IMSLP.org as follows:
Ranges and clefs by Part

More Brahms
Trombone Resources playlist of Brahms with Trombones in the instrumentation.