The American Revolution was a political upheaval that took place between 1765 and 1783 during which the Thirteen American Colonies broke from the British Empire and formed an independent nation, the United States of America. The American Revolution was the result of a series of social, political, and intellectual transformations in American society, government and ways of thinking. Starting in 1765 the Americans rejected the authority of Parliament to tax them without elected representation; protests continued to escalate, as in the Boston Tea Party of 1773, and the British imposed punitive laws—the Intolerable Acts—on Massachusetts in 1774. In 1774 the Patriots suppressed the Loyalists and expelled all royal officials. Each colony now had a new government that took control. The British responded by sending combat troops to re-establish royal control. Through the Second Continental Congress, the Patriots fought the British in the American Revolutionary War (1775 - 1783).

The British sent invasion armies and used their powerful navy to blockade the coast. Former Virginia militia soldier George Washington became the Commander-in-Chief of the Continental Army, working with Congress and the states to raise armies and neutralize the influence of Loyalists. While precise proportions are not known, about 40% of the colonists were Patriots, 20% were Loyalists and the rest were neutral or did not reveal loyalties. As the war continued some changed their loyalties. Claiming British rule was tyrannical and violated the rights of Englishmen, the Patriot leadership professed the political philosophies of liberalism and republicanism to reject monarchy and aristocracy, and proclaimed that all men are created equal. The Continental Congress declared independence in July 1776, when Thomas Jefferson as the primary author, and the Congress unanimously approved an edited version, of the United States Declaration of Independence. Congress rejected British proposals for compromise that would keep them under the king. The British were forced out of Boston in 1776, but then captured and held New York City for the duration of the war, nearly capturing General Washington and his army. The British blockaded the ports and captured other cities for brief periods, but 90% of the inhabitants were in rural areas.
In early 1778, after an invading British army from Canada was captured by the Americans, the French entered the war as allies of the United States. The naval and military power of the two sides were about equal, and France had allies in the Netherlands and Spain, while Britain had no major allies in this large-scale war. The war later turned to the American South, where the British captured an army at South Carolina, but failed to enlist enough volunteers from Loyalist civilians to take effective control. A combined American–French force captured a second British army at Yorktown in 1781, effectively ending the war in the United States. A peace treaty in 1783 confirmed the new nation's complete separation from the British Empire. The United States took possession of nearly all the territory east of the Mississippi River and south of the Great Lakes, with the British retaining control of Canada and Spain taking Florida. Among the significant results of the revolution was the creation of a democratically-elected representative government responsible to the will of the people.