Hardly surprising, since instead of starting from zero, your nation was blessed from the outset by inheriting the best culture, the best system of law, the best system of govt, the ideals of the magna carta and the best language in the world form Britain. America started from the top, not the bottom, so you had most of the hard work already done for you. . . . :D
In all seriousness, there is something about the evolution of English institutions and the character of the English and Scots that has worked out substantially better than our Continental cousins. Perhaps its that uncommon commodity common sense, a sense of proportion and a disinclination radical intellectualism.
It's really interesting. Read English philosophy, especially Locke, Hume, Burke and the like, and the American founders: they're eminently sensible. Read the Continental philosophers like Descartes, the philosophes, Kant, Hegel and their epigoni -- they're all taken with their own brilliance and abstraction almost for its own sake. In the Anglo-sphere, theory serves to illuminate praxis, on the Continent theory is admired for it's own sake. To slightly twist Ernst Cassierer's characterization of the Enlightenment vs. prior Europan thought, the Continent is given to l'esprit de system while the Anglo-sphere is given to l'esprit systematique.
Your knowledge of American history is very wanting.