The answer is: He helped inspire the American Declaration of Independence.
Adam Smith, who was a fundamental part of the Scottish Enlightenment, followed on key ideas of his time —most notably Hume´s philosophical contributions— and developed what is now considered the first theory of modern economics in his greatest work, An Inquiry into the Wealth of Nations. In this book (alongside, The theory of moral sentiments), Smith laid the foundations for the classical free market theory that states, in rough terms, that self-interest and competition can lead to economic prosperity.