The first edition of Walt Whitman's book of poems, Leaves of Grass, is published In Brooklyn.

Leaves of Grass is a poetry collection by American poet Walt Whitman. Though it was first published in 1855, Whitman spent most of his professional life writing and rewriting Leaves of Grass, revising it multiple times until his death. There have been held to be either six or nine individual editions of Leaves of Grass, the count varying depending on how they are distinguished. This resulted in vastly different editions over four decadesthe first edition being a small book of twelve poems, and the last, a compilation of over 400.

The collection of loosely connected poems represents the celebration of his philosophy of life and humanity and praises nature and the individual human's role in it. Rather than focusing on religious or spiritual matters, Leaves of Grass focuses primarily on the body and the material world. With one exception, its poems do not rhyme or follow standard rules for meter and line length.

Leaves of Grass is regarded by many scholars as a completely do-it-yourself project. Whitman chose his idealized self as the subject of the book, created the style in which it was written (working hard and intelligently to perfect the style over a period of six or seven years), and created the personality of the proletarian bardthe supposed writer of the poems.

Leaves of Grass is also notable for its discussion of delight in sensual pleasures during a time when such candid displays were considered immoral. The book was highly controversial during its time for its explicit sexual imagery, and Whitman was subject to derision by many contemporary critics. Over time, however, the collection has infiltrated popular culture and became recognized as one of the central works of American poetry.

Among the works in this collection are "Song of Myself", "I Sing the Body Electric", and "Out of the Cradle Endlessly Rocking". Later editions would include Whitman's elegy to the assassinated President Abraham Lincoln, "When Lilacs Last in the Dooryard Bloom'd".

Walter Whitman (; May 31, 1819 – March 26, 1892) was an American poet, essayist and journalist. A 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 controversial in its time, particularly his 1855 poetry collection Leaves of Grass, which was described as obscene for its overt sensuality. Whitman's own life came under scrutiny for his presumed homosexuality.

Born in Huntington on Long Island, as a child and through much of his career he resided in Brooklyn. At age 11, he left formal schooling to go to work. Later, Whitman worked as a journalist, a teacher, and a government clerk. Whitman's major poetry collection, Leaves of Grass, was first published in 1855 with his own money and became well known. The work was an attempt at reaching out to the common person with an American epic. He continued expanding and revising it until his death in 1892. During the American Civil War, he went to Washington, D.C. and worked in hospitals caring for the wounded. His poetry often focused on both loss and healing. On the death of Abraham Lincoln, whom Whitman greatly admired, he wrote his well known poems, "O Captain! My Captain!" and "When Lilacs Last in the Dooryard Bloom'd", and gave a series of lectures. After a stroke towards the end of his life, Whitman moved to Camden, New Jersey, where his health further declined. When he died at age 72, his funeral was a public event.Whitman's influence on poetry remains strong. Mary Whitall Smith Costelloe argued: "You cannot really understand America without Walt Whitman, without Leaves of Grass ... He has expressed that civilization, 'up to date,' as he would say, and no student of the philosophy of history can do without him." Modernist poet Ezra Pound called Whitman "America's poet ... He is America."