The American Enlightenment is a term sometimes employed to describe the intellectual culture of the British North American colonies and the early United States (as they became known following the American Revolution). It was a part of a larger intellectual movement known as the Age of Enlightenment. Influenced by the scientific revolution of the 17th century, the Enlightenment took scientific reasoning and applied it to human nature, society and religion. Politically the age is distinguished by an emphasis upon liberty, democracy, republicanism and religious tolerance – culminating in the drafting of the United States Declaration of Independence. Attempts to reconcile science and religion resulted in a widespread rejection of prophecy, miracle and revealed religion in preference for Deism – especially by Thomas Paine in "The Age of Reason" and by Thomas Jefferson in his short Jefferson Bible – from which all supernatural aspects were removed.

The Americans, despite their religious background and relative autonomy (growing less by each passing year), were still intimately tied to the English nation. Developments in England, such as the Glorious Revolution, the new scientific methods, and the rise of Parliamentary government, made their way to the colonies as well. The American Enlightenment, which is generally dated from the Glorious Revolution of 1688, was, however, an uneven affair. In part, it involved the exporting of scientific, social, and political ideas from Britain, but also involved the exporting of radical and marginal ideas, such as the republicanism of the "commonwealthmen." In almost all cases, however, the American Enlightenment did not mean the abandonment of the radical Protestant ideas that originally inspired the settlement of America, but started a long process of secularizing these religious ideas. Millenarianism would be caught up in the ideology of republicanism and eventually produce secular ideas such as Manifest Destiny.