What some might call Whitman's essentialism is only one of the features of his statement about the United States that might mark it, in some eyes, as dated, obsolete, historically confined and limited. Another is his use of the plural verb “are,” as opposed to the “is” that gradually became dominant after the American Civil War forever rearranged the notion of an American nation. Only 79 years into the American experiment in 1855, Whitman’s grammar reflects the evolving balance between, on the one hand, the plura of e pluribus and, on the other, the emerging unum under construction. In addition, without listening closely to history, or to various histories, we might not catch the note of desperate, even doomed, hopefulness behind the vatic pronouncement that the United States are essentially the greatest poem. With the passage of the Kansas-Nebraska Act the year before and the first virulent eruptions of the killing that would go on for more than a decade, Whitman is not so much swaggering and flexing as he is urgently speaking a spell or charm against social and political malignancy, even as it too rapidly metastasizes.