The classics scholar William Arrowsmith said that the major ancient Greek tragedies dealt with the meaning of key terms politically-involved Athenians "contested," argued over.
We in the U.S. also have profound disagreements over basic terms. Case in point: America as a "Christian nation" (or a "White Christian nation") vs. the U.S. as a "secular Federal Republic" and not in a meaningful sense a nation at all.
We have no established church (synagog, mosque, or whatever), and Amendment One in our Bill of Rights forbids "an establishment of religion"; and, in a significant omission, "God" isn't mentioned in our Constitution. As a matter of official state policy, we're a secular establishment (which has been quite good for the various religions in American society: they're stronger than in most places with established religion).
And we're not a nation: one "ethnos" — people — with one origin and culture, and a history beginning "back in the mists of time" or even in an origin myth, all united by "blood and soil."
We're a hodgepodge; if you want a fancy image, a mosaic, the one I prefer, that thoroughly American dish, chop suey: one thing, sort of, but in complex ways. Collin Woodard counts "Eleven Regional Cultures of North America," and there are good historical reasons for that kind of regional analysis. For one thing, we're not only still kind of fighting the U.S. Civil War, but also the English struggles of the 17th century that separated out Puritans from less radical Christians.
Plus other ways that we're sliced and diced and divide ourselves up, which on balance is a good thing — *IF*
Our diversity is a good thing if, but only if, most Americans can see ourselves as «One Republic (if we can keep it)», with citizens unified by some agreement on basic terms, plus consciousness of what it's important for us to argue about and dedication to rules of civil contention and competition