Sorry, kat. I got the wrong city -- I meant Des Moines. But here's what Wikipedia says:

A controversial recent hypothesis uses a study of Miami-Illinois tribal names concludes the word Moingona, comes from the word mooyiinkweena, a derogatory name which translates roughly to "the excrement-faces." The name was seemingly given to Marquette and Joliet by a tribal leader to dissuade them from doing business with a neighboring tribe. However, the creator of this etymology admits it is improbable ("strange" as he puts it). This alternative scenario is rejected by the historian Jim Fay, who feels that the interpretation of "Moingona" as "excrement face" is refuted by a large body of first-hand accounts and detailed ethnolinguistic research:

"         These amusing reconstructions and interpretations are more newsworthy, more web popular, and more 'way cool' than the soundly warranted historical evidence, and so, over time, the facts get lost in the shuffle. That seems to be what has happened or is happening to "Moingona." There is no historical record that "shit-faced" was ever expressed or implied in the vernacular usage of the term. There is very substantial evidence to the contrary by probably the most knowledgeable Algonquian linguists who ever lived. Missionaries who understood the language repeatedly used the term, not as a dirty metaphor or ugly insult, but as a very respectful name used in very cordial interactions with the people to whom it referred.

I do hope my point is made, however: as long as it's "us vs. them" labels will be used.