E pluribus unum, or “Out of many, one,” is a motto for the United States—the American States that are united. The many can refer, I suppose, to the sheer number of inhabitants stretching across a continent and beyond. The word could also refer to the diversity of people living even in a large American city. Finally, the word could refer to the Union consists of many different socio-political societies, or republics—again possibly referring to the number of states or the fact that they differ so from one another. It is the last interpretation that I want to explore here, for it alone gets at the fact that the U.S., like the E.U. and China, are at the empire-level (or scale) in twentieth-century (rather than medieval) terms (i.e., scaling).
Yellow: most "religious." Blue: least "religious" (as per regular attendance). Notice the "river" of yellow running through the (political) "red states" in the middle of the map. Even so, "yellow" is doubtless not homogenous.
The complete essay is at "Is the E.U. a Federal System?"