Walt Whitman was an American poet born in 1819 in New York and died in 1892 in New Jersey. He self-published his collection Leaves of Grass in 1855 which broke conventions by using free verse without rhyme. Whitman is considered one of the most important American poets of the 19th century and wrote patriotic poems like "O Captain! My Captain!" about Abraham Lincoln after his assassination. He worked as a nurse during the Civil War caring for wounded soldiers.