Most of the poems in the collection reflect on the American Civil War (1861–1865), including the elegies "When Lilacs Last in the Dooryard Bloom'd" and "O Captain!

The poems of this book were later included in Leaves of Grass, Whitman's comprehensive collection of his poetry that was frequently expanded throughout his life.

After the publication and printing of Drum-Taps in Brooklyn in April 1865, Whitman intended to supplement the collection with several additional Civil War poems and a handful of new poems mourning the assassination of President Abraham Lincoln that he had written between April and June 1865.

After returning to Washington, D.C., in Summer 1865, Whitman contracted with Gibson Brothers to publish a pamphlet of eighteen poems—which he intended to include with copies of Drum-Taps[4]—that would have two works directly addressing the assassination: the elegies "When Lilacs Last in the Dooryard Bloom'd" and "O Captain!

[5] In October, after the pamphlet was printed, Whitman travelled to Brooklyn to collate and bind them into copies of Drum-Taps.