About Leaves of Grass The first edition of his masterpiece,Leaves of Grass,appeared in 1855. Emerson praised Whitman's poetry as "the most extraordinary piece of wit and wisdom that America has yet to contribute." Even Thoreau was appalled by Whitman's poetry,and he was certainly no conformist (follower)！About Leaves of Grass l The first edition of his masterpiece, Leaves of Grass, appeared in 1855. l Emerson praised Whitman’s poetry as “the most extraordinary piece of wit and wisdom that America has yet to contribute.” l Even Thoreau was appalled by Whitman’s poetry, and he was certainly no conformist (follower)!