The influential document that articulated the principles of democracy during the American Revolution was the Declaration of Independence. Authored by Thomas Jefferson in 1776, it outlined the colonies' grievances against the British crown and asserted the inherent rights of individuals to life, liberty, and the pursuit of happiness. This declaration laid the ideological foundation for the U.S. political system and inspired democratic movements worldwide, emphasizing the importance of consent of the governed and the right to self-determination.