Walt Whitman was an American poet born in 1819 in Brooklyn, New York. He left school at age 11 and held various jobs including teacher and newspaper editor. In 1848 he traveled to New Orleans and witnessed the horrors of slavery, which influenced his poetry. He published Leaves of Grass in 1855 to critical acclaim from Ralph Waldo Emerson but controversy over its explicit references. During the Civil War he helped care for wounded soldiers in Washington D.C. Whitman spent his later years in Camden, New Jersey revising and expanding Leaves of Grass, which became his masterwork and established him as a leading American poet.