Walt Whitman was an influential American poet born in 1819 in New York. He worked as a printer and schoolteacher early in his career. Whitman self-published his seminal work, Leaves of Grass, in 1855 which explored themes of democracy, nature, and included free verse style. The book received mixed reviews but helped establish Whitman as a leading voice in American poetry. Later in life, Whitman volunteered as a nurse during the Civil War and wrote poems mourning President Lincoln's assassination. He died in 1892, cementing his legacy as America's poet.