In the following essay, McSweeney studies the relationship between physical health and imaginative power in Whitman's poetry, arguing that the differences in energy and tone between the poems of the 1855 and 1856 editions of Leaves of Grass and those poems added for the 1860 edition can at least in part be attributed to a shift in Whitman's emotional and physical health.

In the following essay, Warren maintains that, through works such as Leaves of Grass and in several essays, Whitman established a theory of language—one directly connected with literature and linguistic development and specifically focused on the significant role of literature in effecting linguistic change and diversity.

In the following essay, Breitwieser suggests that Whitman's usage of multiple voices in Leaves of Grass has political parallels. Breitwieser emphasizes the conflict in the poems between the voice of the small, individual "I" and that of the large, magnanimous, universal "I."

In the following essay, Price examines how prominent sexual themes in Whitman's poetry—such as non-procreative sexuality and female sexuality—influenced later writers of narrative fiction such as Kate Chopin and Hamlin Garland.