Walter Whitman (May 31, 1819 – March 26, 1892) was an American poet, essayist, journalist, and humanist. He was a part of the transition between Transcendentalism and realism, incorporating both views in his works. Whitman is among the most influential poets in the American canon, often called the father of free verse. His work was very controversial in its time, particularly his poetry collection Leaves of Grass, which was described as obscene for its overt sexuality. Whitman's major work, Leaves of Grass, was first published in 1855 with his own money. Whitman was concerned with politics throughout his life. His poetry presented an egalitarian view of the races, and at one point he called for the abolition of slavery, but later he saw the abolitionist movement as a threat to democracy.