W is for Whitman. When Walt Whitman self-published his Leaves of Grass in July 1855, he altered the course of literary history. One of the greatest masterpieces of American literature, it redefined the rules of poetry while describing the soul of the American character. Throughout his life, Whitman continuously revised and expanded the book, but the 1855 original marked Whitman's fresh and bold arrival, greeted by Ralph Waldo Emerson as 'the beginning of a great career.'