video of Rev Bill Darlison talking about Walt Whitman - excellent. They also have videos of Stephen Lingwood's sermons, which are always excellent (he posts them on his blog Reignite too).
Walt Whitman (whilst not a Unitarian) was a key figure in the Transcendentalist movement, which emerged from 19th century Unitarianism.
He was a complex person, believing in the abolition of slavery but disliking the abolitionist movement for its extreme methods, and not believing that African Americans should have the vote.
He is chiefly remembered for his rhythmic poetry, which influenced later poets like Allen Ginsberg, and for his free and celebratory attitude to sexuality, both gay and straight.
By watching the video, you can also find out the connection between Walt Whitman and Bolton.