I'm not sure if Emily Dickinson came under Mount Monadnock's spell, though she is known to have visited Walpole, New Hampshire, which probably would have brought her through Keene and therefore about 15 miles west of the mountain. In addition, she might well have been familiar with Emerson's poem, which was written in 1845 or so. Be that as it may, poem #975 in The Complete Poems of Emily Dickinson, written circa 1864, certainly might make one think of a certain isolated mountain in Cheshire County, New Hampshire...
The Mountain sat upon the Plain
In his tremendous Chair —
His observation omnifold,
His inquest, everywhere —The Seasons played around his knees
Like Children round a sire —
Grandfather of the Days is He
Of Dawn, the Ancestor —