Thoreau and Poe were on completely different ends of the spectrum concerning the period of American Romanticism.  This period consists of multiple views on writing and literature; featuring works that might: focus on the individual or outcast, show an appreciation for nature, feature fantasy, or be revolutionary, introspective, or exotic.

Thoreau valued solitude and experiencing nature to gain knowledge.  InWalden,Thoreau finds that his solitude at Walden Pond brings insight:

In the midst of a gentle rain while these thoughts prevailed, I was suddenly sensible of such sweet and beneficent society in Nature, in the very pattering of the drops."

Thoreau's brand of Romanticism is Transcendental. He adores nature, solitude, and self-discovery.

Poe's view of Romanticism differed dramatically from Thoreau. Whereas Thoreau focused on the deeper meanings of the natural world, Poe's writings are emotional, mysterious, and dark.  Poe's writings focus on the complex individual, emotionally seeking an elusive goal or ideal.  Poe's characters, often of questionable sanity (the unreliable narrator in the "Tell-Tale Heart"), resonate in dark, gothic settings ("The Fall of the House of Usher," "The Masque of the Red Death," "The Pit and the Pendulum").