This article explores how the model of the US cultural policies allows the creation of minority, racial and ethnic museums. It shows the difference between mainstreams museum and the community museums situated in peripheral neighborhoods in Illinois. It shows how the diaspora’s recent museums in Chicago are questioning the imagined nations and how nomadic subjects are grounded and practicing a self-representation in US territory. The text places at the center of its analysis the case of National Museum of Mexican Art of Chicago and the contradiction of the assimilation of Mexican culture by the American hegemony. This article was originally presented in an international workshop about Migration and Museum in Paris, at the EHESS in 2009. The reader will find references to the French context throughout the text. This comparison is important because the French model of cultural policies doesn’t allow a self-representation of minorities.