American exceptionalism refers to the theory that the United States is qualitatively different from other nations. In this view, America's exceptionalism stems from its emergence from a revolution, becoming "the first new nation", and developing a uniquely American ideology, based on liberty, egalitarianism, individualism, populism and laissez-faire. This observation can be traced to Alexis de Tocqueville, the first writer to describe the United States as "exceptional". The term "American exceptionalism" itself was first used by members of the American Communist Party in the 1920s, in reference to their belief that "thanks to its natural resources, industrial capacity, and absence of rigid class distinctions, America might for a long while avoid the crisis that must eventually befall every capitalist society."
Of course, the entry goes on in some detail, but the broad concept is pretty much all there; America is a unique nation for many reasons. Personally, I believe the most important distinction is that we are a nation founded in law -- we exist for a reason. Where other nations may exist because of ethnic or religious identity, America does not. And we aren't defined by our existence within the borders of an ancient monarchy or tribe. "I am American" means something very different from "I am French," for example.
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