I caught the end of a documentary on Walt Whitman just now and this is the end of it actually.
The last stanza of this poem - it had me in tears. The things he's sensitive too are nothing like what people of today are sensitive about.
But more than being able to notice these things, he was able to express them in words.
He bequeathed his anthology (35 years of work) to anyone who would have it apparently.
Unbelievable! It's one very long poem. Dare you to read it through: Here