American Revolution, 1775?83, struggle by which the Thirteen Colonies on the Atlantic seaboard of North America won independence from Great Britain and became the United States. It is also called the American War of Independence.

Causes and Early Troubles
By the middle of the 18th cent., differences in life, thought, and interests had developed between the mother country and the growing colonies. Local political institutions and practice diverged significantly from English ways, while social customs, religious beliefs, and economic interests added to the potential sources of conflict. The British government, like other imperial powers in the 18th cent., favored a policy of mercantilism; the Navigation Acts were intended to regulate commerce in the British interest. These were only loosely enforced, however, and the colonies were by and large allowed to develop freely with little interference from England.

Conditions changed abruptly in 1763. The Treaty of Paris in that year ended the French and Indian Wars and removed a long-standing threat to the colonies. At the same time the ministry (1763?65) of George Grenville in Great Britain undertook a new colonial policy intended to tighten political control over the colonies and to make them pay for their defense and return revenue to the mother country. The tax levied on molasses and sugar in 1764 caused some consternation among New England merchants and makers of rum; the tax itself was smaller than the one already on the books, but the promise of stringent enforcement was novel and ominous.

It was the Stamp Act, passed by the British Parliament in 1765, with its direct demand for revenue that roused a violent colonial outcry, which was spearheaded by the Northern merchants, lawyers, and newspaper publishers who were directly affected. Everywhere leaders such as James Otis, Samuel Adams, and Patrick Henry denounced the act with eloquence, societies called the Sons of Liberty were formed, and the Stamp Act Congress was called to protest that Parliament was violating the rights of trueborn Englishmen in taxing the colonials, who were not directly represented in the supreme legislature. The threat of boycott and refusal to import English goods supported the colonial clamor. Parliament repealed (1766) the Stamp Act but passed an act formally declaring its right to tax the colonies.

The incident was closed, but a barb remained to wound American feelings. Colonial political theorists?not only radicals such as Samuel Adams, Patrick Henry, Josiah Quincy (1744?75), and Alexander McDougall but also moderates such as John Dickinson, John Adams, and Benjamin Franklin?asserted that taxation without representation was tyranny. The teachings of 18th-century French philosophers and continental writers on law, such as Emmerich de Vattel, as well as the theories of John Locke, were implicit in the colonial arguments based on the theory of natural rights. The colonials claimed that Parliament had the sovereign power to legislate in the interest of the entire British Empire, but that it could only tax those actually represented in Parliament.

Trouble flared when the Chatham ministry adopted (1767) the Townshend Acts, which taxed numerous imports; care was taken to levy only an ?external? or indirect tax in the hope that the colonials would accept this. But this indirect tax was challenged too, and although the duties were not heavy, the principle was attacked. Incidents came in interrupted sequence to make feeling run higher and higher: the seizure of a ship belonging to John Hancock in 1768; the bloodshed of the Boston Massacre in 1770; the burning of H. M. S. Gaspee in 1772.

The First Continental Congress
The repeal of the Townshend Acts in 1770 did no more than temporarily quiet the turmoil, for the tax on tea was kept as a sort of token of Parliament's supremacy. Indignation in New England at the monopoly granted to the East India Company led to the Boston Tea Party in 1773. Despite the earnest pleas of William Pitt the elder and Edmund Burke, Parliament replied with coercive measures.

These (and the Quebec Act) the colonials called the Intolerable Acts, and resistance was prompt. The Sons of Liberty and individual colonials were already distributing statements of the colonial cause to win over merchant and farmer, worker and sailor. Committees of correspondence had been formed to exchange information and ideas and to build colonial unity, and in 1774 these committees prepared the way for the Continental Congress.

The representatives at this First Continental Congress, except for a few radicals, had not met to consider independence, but wished only to persuade the British government to recognize their rights. A plan of reconciliation offered by Joseph Galloway was rejected. It was agreed that the colonies would refuse to import British goods until colonial grievances were righted; those grievances were listed in petitions to the king; and the congress adjourned.

War's Outbreak
Before Congress met again the situation had changed. On the morning of Apr. 19, 1775, shots had been exchanged by colonials and British soldiers, men had been killed, and a revolution had begun. On the very day (May 10, 1775) that the Second Continental Congress met, Ethan Allen and his Green Mountain Boys, together with a force under Benedict Arnold, took Fort Ticonderoga from the British, and two days later Seth Warner captured Crown Point. Boston was under British siege, and before that siege was climaxed by the costly British victory usually called the battle of Bunker Hill (June 17, 1775) the Congress had chosen (June 15, 1775) George Washington as commander in chief of the Continental armed forces.

Indecision and Declaration
The war was on in earnest. Some delegates had come to the Congress already committed to declaring the colonies independent of Great Britain, but even many stalwart upholders of the colonial cause were not ready to take such a step. The lines were being more clearly drawn between the pro-British Loyalists and colonial revolutionists. The time was one of indecision, and the division of the people was symbolized by the split between Benjamin Franklin and his Loyalist son, William Franklin.

Loyalists were numerous and included small farmers as well as large landowners, royal officeholders, and members of the professions; they were to be found in varying strength in every colony. A large part of the population was more or less neutral, swaying to this side or that or else remaining inert in the struggle, which was to some extent a civil war. So it was to remain to the end.

Civil government and administration had fallen apart and had to be patched together locally. In some places the result was bloody strife, as in the partisan raids in the Carolinas and Georgia and the Mohawk valley massacre in New York. Elsewhere hostility did not produce open struggles.

In Jan., 1776, Thomas Paine wrote a pamphlet, Common Sense, which urged the colonial cause. Its influence was tremendous, and it was read everywhere with enthusiastic acclaim. Militarily, however, the cause did not prosper greatly. Delegations to the Canadians had been unsuccessful, and the Quebec campaign (1775?76) ended in disaster. The British gave up Boston in Mar., 1776, but the prospects were still not good for the ill-trained, poorly armed volunteer soldiers of the Continental army when the Congress decided finally to declare the independence of the Thirteen Colonies.

The Declaration of Independence is conventionally dated July 4, 1776. Drawn up by Thomas Jefferson (with slight emendations), it was to be one of the great historical documents of all time. It did not, however, have any immediate positive effect.

The British under Gen. William Howe and his brother, Admiral Richard Howe, came to New York harbor. After vain attempts to negotiate a peace, the British forces struck. Washington lost Brooklyn Heights, retreated northward, was defeated at Harlem Heights in Manhattan and at White Plains, and took part of his dwindling army into New Jersey. Thomas Paine in a new pamphlet, The Crisis, exhorted the revolutionists to courage in desperate days, and Washington showed his increasing military skill and helped to restore colonial spirits in the winter of 1776?77 by crossing the ice-ridden Delaware and winning small victories over forces made up mostly of Hessian mercenaries at Trenton (Dec. 26) and Princeton (Jan. 3).

Saratoga and Valley Forge
In 1777 the British attempted to wipe out the flickering revolt by a concerted plan to split the colonies with converging expeditions concentrated upon the Hudson valley. Gen. William Howe, instead of taking part in it, moved into Pennsylvania, defeated Washington in the battle of Brandywine (Sept. 11), took Philadelphia, and beat off (Oct. 4) Washington's attack on Germantown. Meanwhile the British columns under Gen. John Burgoyne and Gen. Barry St. Leger had failed, and Burgoyne on Oct. 17, 1777, ended the battle of Saratoga by surrender to Gen. Horatio Gates. The victory is commonly regarded as the decisive battle of the war, but its good effects again were not immediate.

The Continental army still had to endure the hardships of the cruel winter at Valley Forge, when only loyalty to Washington and the cause of liberty held the half-frozen, half-starved men together. Among them were three of the foreign idealists who had come to aid the colonials in their struggle?Johann Kalb, Baron von Steuben, and the marquis de Lafayette. At Valley Forge, Steuben trained the still-raw troops, who came away a disciplined fighting force giving a good account of themselves in 1778. Sir Henry Clinton, who had succeeded Howe in command, decided to abandon Philadelphia for New York, and Washington's attack upon the British in the battle of Monmouth was cheated of success mainly by the equivocal actions of Gen. Charles Lee.

Foreign Assistance
The warfare in the Middle Atlantic region settled almost to stagnation, but foreign aid was finally arriving. Agents of the new nation?notably Benjamin Franklin, Arthur Lee, Silas Deane, and later John Adams?were striving to get help, and in 1777 Pierre de Beaumarchais had succeeded in getting arms and supplies sent to the colonials in time to help win the battle of Saratoga. That victory made it easier for France to enter upon an alliance with the United States, for which Franklin and the comte de Vergennes (the French foreign minister) signed (1778) a treaty. Spain entered the war against Great Britain in 1779, but Spanish help did little for the United States, while French soldiers and sailors and especially French supplies and money were of crucial importance.

Vincennes to Yorktown
The warfare had meanwhile shifted from the quiescent North to other theaters. George Rogers Clark by his daring exploits (1778?79) in the West, climaxed by the second capture of Vincennes, established the revolutionists' prestige on the frontier. Gen. John Sullivan led an expedition (1779) against the British and Native Americans in upper New York.

The chief fighting, however, was now in the South. The British had taken Savannah in 1778. In 1780, Sir Henry Clinton attacked and took Charleston (which had resisted attacks in 1776 and 1779) and sent Gen. Charles Cornwallis off on the Carolina campaign. Cornwallis swept forward to beat Horatio Gates soundly at Camden (Aug., 1780), and only guerrilla bands under Francis Marion, Andrew Pickens, and Thomas Sumter continued to oppose the British S of Virginia.

Another low point had been reached in American fortunes. Bitter complaints of the inefficiency of the Congress, political conniving, lack of funds and food, and the strains of long-continued war had engendered widespread apathy and disaffection, and the British tried to take advantage of the division among the people. In 1780 occurred the most celebrated of the disaffections, the treason of Benedict Arnold. Lack of pay and shortages of clothing and food drove some Continental regiments into a mutiny of protest in Jan., 1781.

The dark, however, was already lifting. A crowd of frontiersmen with their rifles defeated a British force at Kings Mt. in Oct., 1780, and Nathanael Greene, who had replaced Gates as commander in the Carolina campaign, and his able assistant, Daniel Morgan, together with Thaddeus Kosciusko and others, ultimately forced Cornwallis into Virginia. The stage was set for the Yorktown campaign.

Now the French aid counted greatly, for Lafayette with colonial troops held the British in check, and it was a Franco-American force that Washington and the comte de Rochambeau led from New York S to Virginia. The French fleet under Admiral de Grasse played the decisive part.

Previously naval forces had been of little consequence in the Revolution. State navies and a somewhat irregular national navy had been of less importance than Revolutionary privateers. Esek Hopkins had led a raid in the Bahamas in 1776, John Barry won a name as a gallant commander, and John Paul Jones was one of the most celebrated commanders in all U.S. naval history, but their exploits were isolated incidents.

It was the French fleet?ironically, the same one defeated by the British under Admiral Rodney the next year in the West Indies?that bottled up Cornwallis at Yorktown. Outnumbered and surrounded, the British commander surrendered (Oct. 19, 1781), and the fighting was over. The rebels had won the American Revolution.

Aftermath
The Treaty of Paris formally recognized the new nation in 1783, although many questions were left unsettled. The United States was floundering through a postwar depression and seeking not too successfully to meet its administrative problems under the Articles of Confederation.

The leaders in the new country were those prominent either in the council halls or on the fields of the Revolution, and the first three Presidents after the Constitution of the United States was adopted were Washington, Adams, and Jefferson. Some of the more radical Revolutionary leaders were disappointed in the turn toward conservatism when the Revolution was over, but liberty and democracy had been fixed as the highest ideals of the United States.

The American Revolution had a great influence on liberty thought throughout Europe. The struggles and successes of the youthful democracy were much in the minds of those who brought about the French Revolution, and most assuredly later helped to inspire revolutionists in Spain's American colonies.