The main way in which the Enlightenment affected the American colonists was by encouraging them to think that monarchy was bad, democracy was good, and that people have natural rights that should be protected.
The Enlightenment was a time when people started to think that rationality was to be prized above other kinds of thought. Before the Enlightenment people tended to base their thinking on what people of the past had thought. They especially relied on what religious leaders told them. During the Enlightenment, this changed. People started to demand that what they were told should make rational sense. It should not depend on supernatural forces.
This thinking changed the way people thought about politics. The institution of monarchy was something that people only accepted because it was traditional and because of religion. Monarchs were said to have been chosen by God and to rule by divine right. This belief depends on supernatural forces and cannot be supported logically or rationally. Therefore, people started to reject the idea of monarchy.
Instead, people started to think about democracy. Thinkers like John Locke thought rationally about why there is government and what government should do. They decided that government only exists by the consent of the people and that it only exists to protect the people’s rights. These ideas gained a great deal of support in the American colonies and helped to bring about the American Revolution.
The Enlightenment, then, affected the American colonists by encouraging them to think in ways that led them to reject monarchy and to move towards the idea that government should be democratic and should protect the rights of the people. This kind of thinking led to the American Revolution.