The revolution provided America with a unifying ideology that allowed equality to become a stronger part of the American idea of freedom. Before the revolution, the American colonies were a disparate collection of settlements which had been founded for various reasons by groups of people who had little in common. The revolution could not entirely bring these people together, nor could it make them true to the principles of the new republic. However, it could and did produce founding documents which stated in the most eloquent terms precisely what those principles were.
The Declaration of Independence places the idea "that all men are created equal" first among its self-evident truths. Although it often seems hypocritical to twenty-first century readers that the principle of equality should be asserted in this way by aristocratic slave-owners, it is important to remember that the British and other Europeans had neither the principle nor the practice.
Once the principle of equality had been so boldly asserted there was a clearer impetus for conscientious citizens to strive after a more equal society. In the old world, most people, and certainly most members of the landowning class, had not even seen equality as desirable, much less attainable.
Perhaps the clearest example of increased equality is the abolition of slavery. A statute providing for gradual emancipation was passed in Pennsylvania in 1780 (see article attached below), and one abolishing slavery entirely became law in Massachusetts three years later. Many of the Northern states followed suit in the ensuing decades.