-Fourth Edition

Whitman initially believed that with the third edition of Leaves of Grass in 1860 he had finally completed his book, so he went on to publish two separate books of poems about the U.S. Civil War: Drum-Taps (1865) and Sequel to Drum-Taps (1865-66). In 1867, however, Whitman included the poems from both books into a revised and expanded fourth edition of Leaves of Grass, signaling his intention to have his book grow and evolve as both he and his nation went through the major transformations of the nineteenth century.