Imagery brings the poem's world to life, evoking both the joy of spring and the pain of grief through vivid, sensuous description.
The poem is set in a springtime world full of lilac bushes with "heart-shaped leaves of rich green." And even as Lincoln’s funeral train makes its sad journey, it moves through landscapes full of “grass in the fields,” “yellow-spear’d wheat,” and "apple-tree blows of white and pink."
By sections 10 and 11, when the speaker imagines what he could bring to Lincoln’s grave, his imagery expands to conjure "pictures" of the entire United States, including “sea-winds” off the coasts, "floods of the yellow gold of the gorgeous, indolent, sinking sun," and "the gray smoke lucid and bright." This varied imagery conveys the richness of the land that the speaker celebrates, and by extension the vibrancy of the U.S. itself.
When the speaker moves away from the activity of the living world to approach the singing bird in the swamp, the imagery of the poem changes. This "dim" place, so different from the active brightness of earlier landscapes, allows the speaker to meditate on death; he envisions "battle-corpses" and "the white skeletons of young men."
Section 16's final procession of imagery, in which familiar images like the starry "comrade lustrous with silver face in the night" and "the fragrant pines and the cedars dusk and dim" return and combine, brings together celebration and grief. Both life and death, the poem's imagery finally suggests, are part of a vibrant whole.