:In this article, the inhabitants of the thirteen colonies that supported the American Revolution are primarily referred to as "Americans", with occasional references to "Patriots", "Whigs", "Rebels", or "Revolutionaries". Colonists who supported the British in opposing the Revolution are usually referred to as "Loyalists" or "Tories". (See section 2 below for a detailed explanation.) The geographical area of the thirteen colonies that both groups shared is often referred to simply as "America".

Category: Image - :Declaration independence.jpg|thumb|300px|John Trumbull's Declaration of Independence, showing the five-man committee in charge of drafting the Declaration in 1776 as it presents its work to the Second Continental Congress in Philadelphia

The American Revolution refers to the political upheaval during the last half of the 18th century in which the Thirteen Colonies of North America overthrew the governance of the British Empire and collectively became the nation of the United States of America. In this period, the colonies first formed self-governing independent states, and then united against the British to defend that self-governance from 1775 to 1783 in the armed conflict known as the American Revolutionary War (or the "American War of Independence"). This resulted in the states breaking away from the empire with the Declaration of Independence in 1776, effective victory on the battlefield in October 1781, and British recognition of United States sovereignty and independence in 1783.

The revolutionary era began in 1763, when the French military threat to British North American colonies ended. Adopting the policy that the colonies should pay an increased proportion of the costs associated with keeping them in the Empire, Britain imposed a series of taxes followed by other laws intended to demonstrate British authority that proved extremely unpopular. Because the colonies lacked elected representation in the governing British Parliament many colonists considered the laws to be illegitimate and a violation of their rights as Englishmen. In 1772, Patriot groups began to create committees of correspondence, which would lead to their own Provincial Congress in most of the colonies. In the course of two years, the Provincial Congresses or their equivalents effectively replaced the British ruling apparatus in the former colonies, culminating in 1774 with the unifying First Continental Congress.

In response to Patriot protests in Boston over British attempts to assert authority, the British sent combat troops. Consequently, the states mobilized their militias, and fighting broke out in 1775. Although Loyalists were estimated to comprise 15-20% of the population,Calhoon, "Loyalism and neutrality" in Greene and Pole, A Companion to the American Revolution (2000) p.235 throughout the war the Patriots generally controlled 80-90% of the territory; the British could hold only a few coastal cities for any extended period of time. In 1776, representatives from each of the original thirteen independent states voted unanimously to adopt a Declaration of Independence, establishing the United States, which was originally governed as a loose confederation by a representative government selected by state legislatures (see Second Continental Congress). The Americans formed an alliance with France in 1778 that evened the military and naval strengths, later bringing Spain and the Dutch Republic into the conflict by their own alliance with France. Two main British armies were captured by the Continental Army, at Saratoga in 1777 and Yorktown in 1781, that amounted to victory in the war for the United States. The Second Continental Congress transitioned to the Congress of the Confederation with the ratification of the Articles of Confederation earlier in 1781. The Treaty of Paris in 1783 was ratified by this new national government, and ended British claims to any of the thirteen states.

The American Revolution included a series of broad intellectual and social shifts that occurred in the early American society, such as the new republican ideals that took hold in the American population. In some states, sharp political debates broke out over the role of democracy in government, with a number of even the most liberal Founding Fathers fearing mob rule.

Many issues of national governance were not settled until the Constitution of the United States (1787), including the first 10 amendments in the United States Bill of Rights (1789), replaced the relatively weak Articles of Confederation (see Federalist Papers''). The Constitution, by contrast, enshrined the natural rights idealized by republican revolutionaries and guaranteed them under a relatively strong federated government, as well as dramatically expanding suffrage for national elections. The American shift to republicanism, and the gradually increasing democracy, caused an upheaval of the traditional social hierarchy, and created the ethic that formed the core of American political values.Wood (1992); Greene & Pole (1994) ch 70