What are Whitman's poems about war?

Leaves of Grass is a famous collection of poems, which was basically created during the American Civil War, among which Leaves of Grass occupies a special position and is regarded as an epic during the American Civil War. The poet himself said with satisfaction that it is "relatively complete as a work of art" ... expressing my creative ambition that I often think about, that is, expressing our times and country in poetry, together with all bloody things.