I think that "the task eternal" is the development of the United States. The stanza where the phrase appears open with "Have the elder races halted?" Such a question brings to light that Whitman believes the future of the United States is similar to the advancement of the Pioneers, one where democratic vistas are embraced with a frontier line that is boundless. This energy and zeal is predominantly a young person's "game" for Whitman. The language he uses to describe the predecessors of the Pioneers brings to light that he believes the task of redefining the geographic, political, social, and aesthetic landscape of America is something thar resides with young people. The manner in which this will be accomplished is through a sense of embracing the task as a cohesive entity. In identifying the sense of national character within definition that links all of the "pioneers," Whitman is convinced that this is a destiny that all Americans can embrace.