The American Revolution was a political upheaval in which the 13 American colonies rejected British rule and formed an independent nation. Dissatisfaction grew due to taxation without representation and harsh legislation from Parliament restricting settlement and trade. Inspired by Enlightenment ideas of natural rights and republicanism, Patriots and Loyalists took sides as tensions escalated. Events like the Boston Massacre, the Tea Party, and battles at Lexington and Concord marked the start of armed conflict. On July 4, 1776, the Declaration of Independence was approved, establishing the United States.