By nature of its geographic location alone, America has always represented something "set apart" from everything that came before. Among the early European settlers to the New World were persecuted religious minorities seeking the freedom to practice their faith in peace. Puritan leader John Winthrop believed that America was the new Promised Land and that the faithful were to "be as a city upon the hill" in their New Jerusalem [source: USHistory.org].
But to really understand what made America exceptional from the start, you have to look at two remarkable founding documents: the Declaration of Independence and the Constitution. The Declaration of Independence lays out the democratic ideals and values of the new nation: that the right to rule is derived from the "consent of the governed," that "all men are created equal" and endowed by God with certain rights, among them "life, liberty and the pursuit of happiness."
These democratic principles were not distinctly "American," since they were developed by European Enlightenment philosophers like John Hobbes (equality as natural state), John Locke ("inalienable rights" of life and liberty), and Jean-Jacques Rousseau (consent of the governed) [source: Constitutional Rights Foundation]. But America was the first nation to enshrine those ideals as the basis of a government.
America is fundamentally exceptional, therefore, because it was founded upon an idea. Prior to the Declaration of Independence, nations had evolved from tribal associations, common languages and the will of an elite few exercising their power over many. The fact that America was founded on shared moral and political principles rather than shared ancestry meant that anyone who embraced these ideals — no matter where they were born or their socioeconomic status — was now an American.
The Constitution is another exceptional document. While the Bill of Rights gets a lot of love (and rightfully so) for safeguarding individual freedoms against government tyranny, the basic structure of the federal government as outlined in the Constitution was also a game-changer.
The U.S. government was the first to explicitly distribute the federal government's power between three "separate but equal branches": the legislative to write the laws, the judiciary to interpret the laws and the executive branch to enforce them. (You can thank French philosopher Baron de Montesquieu for that one.) This system of checks and balances all but guarantees gridlock, but also ensures that no individual president or majority party can act with impunity.
So that's the historical foundation of American exceptionalism, but when was the term first coined and how was it used? This one might surprise you.