I assume you mean what the poem was about, because Poe wrote all of his poetry for paid publication and to tap into the wellspring of his feelings. This was an early effort, short and, I think, later not so well thought-of by Poe himself. read more
The poem was not included in Poe's second poetry collection, Al Aaraaf, Tamerlane, and Minor Poems, and was never re-printed during his lifetime."Evening Star" was adapted by choral composer Jonathan Adams into his Three Songs from Edgar Allan Poe in 1993. read more