Which of the following was a 'Nature Poet'?

Concept: In literary history, several English writers are remembered by a fixed descriptive epithet that names the dominant theme or innovation of their work -- the title works almost like a one-word substitution, identifying the writer without using their name. A writer earns the 'Nature Poet' epithet only when nature is not just a background setting but the central, defining subject and inspiration of nearly all their major poetry.

Application: William Wordsworth earned exactly this title -- first given to him by Percy Bysshe Shelley as 'Poet of Nature' -- because collections such as Lyrical Ballads (with Coleridge), 'Tintern Abbey', and 'I Wandered Lonely as a Cloud' treat nature as a moral and spiritual teacher, not mere scenery. This worship of nature as a living, guiding presence runs through nearly his entire body of work, which is why literary history singles him out with this specific epithet.

Cross-check: Each of the other three carries its own distinct standard epithet, none of them 'Nature Poet':

• Edgar Allan Poe is remembered as the 'Father of Detective Fiction' for inventing the modern detective story with C. Auguste Dupin; his signature subject is mystery and the macabre, not nature.

• Wole Soyinka is a Nigerian playwright and the first African Nobel laureate in Literature (1986), celebrated for drama rooted in Yoruba ritual and myth -- not for nature poetry.

• Walt Whitman carries his own separate epithet, the 'Father of Free Verse', earned for breaking away from fixed meter and rhyme in Leaves of Grass; that title is about the FORM of his poetry, not nature as its defining subject.

So among the four, only Wordsworth carries the specific 'Nature Poet' title.