Possible Clues:

• Initially Forster expresses hesitation about US poet
• Thoreau's essayist friend
• Poet dubbed 'Sage of Concord'
• Philosopher making me regress, powerless individual
• US writer delivering awful sermon about English
• ''Self-Reliance'' essayist
• Lear knew him well enough, and his name
• Jay Leno alma mater
• American author, 1803-82
• Looking back, sopranos remember entertaining poet