In answering this question it is important to ask if the Revolution was an extension of the principles of English democracy and freedom, or if it was motivated by the principles of the European-wide Enlightenment of the eighteenth-century. One, moreover, has to ask if those two bodies of intellectual thinking, or ideals, were interrelated.
The answer to "all of the above" is yes. European progressives had long looked to England as the one nation in which there was a degree of personal freedom, and a limitation on the power of the monarchy, beyond that of the other countries. This became even more evident after the English Revolution of 1688 in which James II was overthrown and Parliament, representing the people directly (though at this point very imperfectly), gained more authority than ever before. A reciprocal process was in place between political developments and intellectual thought. The philosophers John Locke and, later, David Hume were enormously influential upon the European Enlightenment, Locke with his ideas of limited government and the ideal of government being an instrument of the people, and Hume with his secular thinking.
All of this formed the background of the American Revolution. What began as a resistance movement to the taxation schemes of the Crown became, in 1776, the founding of a country based on ideals. The Declaration of Independence encapsulates both of the philosophical points we have mentioned: government functioning as a means to secure the freedom and the rights of people, and (though not explicitly stated in the Declaration) secularism.
Though Americans were unable or unwilling to implement these ideals fully at the time, the fact that they were stated became a promise that eventually, there would be a fulfillment of them. The process of this fulfillment is ongoing, and is continuing to take place now, but it is significant that 242 years ago, a visionary document was produced that was a kind of birth certificate for a country created by ideas—ideas which represent the better side of human nature.