When breaking down the essence of America in this way, it becomes possible for a few key events to float to the top of each category as being critical in the evolution of the United States. Of course, this determination is largely a matter of opinion. Nevertheless, a concrete case can be made for three major historical developments as the most essential factors shaping America. In the political realm, the Enlightenment is the first factor. In the economic realm, the Industrial Revolution is the second factor. And in the military realm, World War II is the third factor. Taken together, these three factors comprise a triad of events in whose absence the America we know today could never have possibly come into being.
The Enlightenment was arguably the most important historical event influencing the United States governmental and political system. Not only did it spawn a philosophy of good government and a view of human rights that directly impacted the thinking of the Founding Fathers as they crafted the American system of government, but it also indirectly informed modern views of social justice that precipitated such developments as the Civil Rights movement, universal suffrage, and social security. The Enlightenment, while more of a European phenomenon than an American one, took place at just the right time, directly preceding the American Revolution and heavily influencing the thinking of the great men who would be instrumental in setting the initial course of America (http://www.wsu.edu/dee/AMERICA/ENLIGHT.HTM).
The Enlightenment was the point in history when some of the most influential political philosophers of history wrote their seminal works. These include the writings of John Locke, Jean-Jacques Rousseau, Thomas Hobbes, and John Stuart Mill. Together, these great thinkers laid out the philosophical underpinnings of what would become the American government. Such concepts as separation of powers, the right to life, liberty and property, the importance of a strong central government, and the common good, all came into play as the Framers developed their formula of "good government" that is laid out within the U.S. Constitution. These "enlightened" thinkers, among others, brought about a fundamental shift in the way humans viewed their world and their natural place in it. The Enlightenment essentially set the philosophical parameters surrounding the way humans interact with one another and agree to govern one another.
The Founding Fathers, most notably James Madison and Thomas Jefferson, injected a heavy dose of Enlightenment philosophy into the American governmental system, with its protection against the tyranny of the majority, its preservation of individual liberty and property rights, and its perpetuation of the sovereignty of the states in the face of a strong central government. As such, the Enlightenment provided the cornerstone of American government, and was perhaps the most critical world historical event shaping America.
The Industrial Revolution
Just as the Enlightenment was key to America's political development, the Industrial Revo