"Pioneers! O Pioneers!" is a paean of praise to the pioneers, those Americans who, by great effort, succeeded in transforming wilderness into civilization. Whitman identifies himself, body and soul, with them and is determined to march on the road to progress. The poet appears as a prophet — like Moses, he will lead the modern Israelites to a new Promised Land.
"Tan-faced children" and "Western youths" are called upon to fell "primeval forests" and to cross rivers and mountains in order to reach the West. Some of these pioneers "droop and die" on their journey. But, cheered on by "all the pulses of the world," the rest will reach their goal.
In this poem it is suggested that the movement of Americans to the West is another way of fulfilling a divine purpose; it is one form of the fruition of mystic evolution, of the material and spiritual progress of man.