What exactly is a Calumet?
“In arriere the peace talk with the Iroquois the aborigines, the calumet, the pipe of good-will, arbitration, and indrosement.” (“Our Old Feuillage” page 321)
According to dictionary.com, the calumet is:
“a long-stemmed, ornamented tobacco pipe used by North American Indians on ceremonial occasions, esp. in token of peace.”
How this functions then, in terms of Whitman’s poetry is that it adds a tone of authenticity to the piece. Knowing the lingo, so to speak of a culture leads the reader to put more stock in your words because you know what you are talking about. The confusion, though, that lead to this image gloss was in the ambiguity in the lines, where Whitman is moving from peoples, the Iroquois and aborigines, to the pipe of good will mentioned afterwords.