Walter Whitman (1819-1892) 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 is also very controversial, particularly his poetry collection Leaves of Grass, which has been described as obscene for its overt sexuality. He worked as a journalist, a teacher, a government clerk, and a volunteer nurse during the American Civil War in addition to publishing his poetry. Early in his career, he also produced a temperance novel, Franklin Evans (1842). Whitman's major work was Leaves of Grass. The work was an attempt at reaching out to the common man with an American epic. He continued expanding and revising it until his death. He was also concerned with politics throughout his life. He supported the Wilmot Proviso but did not believe in the abolitionist movement.