This document summarizes the key influences on American democracy from ancient Greece and Rome to Enlightenment thinkers. It discusses how ancient Athens used both direct and indirect forms of democracy which were adapted by the U.S. Founding Fathers. Other influences included the Roman separation of powers, limitations on the British monarchy established by the Magna Carta and English Bill of Rights, and the Judeo-Christian belief in equality before God. Enlightenment philosophers like Locke, Montesquieu, Beccaria and Voltaire advocated for natural rights, separation of powers, more humane treatment of criminals, and freedom of speech.