American War of Independence, 1775–83. The roots of American independence go as deep as the original settlements—colonists of a dissenting disposition with little cause for affection for their mother country, the development of a more egalitarian society without bishops or noblemen, colonial assemblies gaining political experience and anxious to extend their privileges, and a population increasing in size, prosperity, and confidence. In 1715 the colonists numbered fewer than half a million, of whom 70,000 were negro slaves. By 1770 there were more than 2 million. The ties with England were already weakening as many of the new settlers—Germans, Swiss, or Ulster-Irish—had no English connections. (See America.)

The crisis was triggered off by the Seven Years War, during which the British drove the French out of Canada. It had often been remarked that only the threat of falling prey to Spain or France kept the colonists in check. That check was removed at exactly the moment that the British became alarmed at the rising cost of the plantations: they were anxious to reduce clashes with the Indians and determined that the Americans should bear more of the imperial burden. The first objective produced a prohibition on expansion across the Allegheny mountains, the second produced Grenville's Stamp Act of 1764, which led to a storm of protest. Though the Stamp Act was repealed in 1766, the Declaratory Act which reaffirmed British sovereignty deprived the gesture of much of its appeal. The imposition of the Townshend duties provoked violence and the situation escalated. The Boston massacre of 1770 was followed by the seizure of the Gaspée in 1772 and the Boston Tea Party in 1773. By 1774 the Americans had summoned a congress to concert resistance and most Britons were convinced that the lawlessness of the colonists could not be tolerated.

Once fighting began at Lexington in 1775, Britain faced a difficult military task. To occupy and garrison so vast a country was out of the question. But many Americans, especially in the south, remained loyal to the crown and British armed intervention could give them the upper hand against the patriots. The first phase finished when Burgoyne's grandiose plan to drive down the Hudson river from Canada and cut off New England ended in capitulation at Saratoga in October 1777. Though the disaster could have been retrieved, it brought France and Spain into the conflict and placed in jeopardy Britain's command of the seas. Nevertheless the issue remained in doubt and Washington experienced great difficulty in holding his troops together. In 1780 Cornwallis led a major expedition to the southern colonies. He was cut off and his surrender at Yorktown in October 1781 brought the conflict to an end. American independence was recognized by the treaty of Versailles in 1783.

The short-term consequences were less dramatic than many expected. Though Britain's eclipse as a world power was confidently predicted, her economic recovery was swift, and the colonial development of Australia, New Zealand, India, and parts of Africa went some way to compensating for the loss of the first British empire. But in the long run there was a great shift of power across the Atlantic and the population of the USA passed that of the mother country soon after the American Civil War, in the 1860s. In the long perspective of world events, the colonization and the loss of America, together with the spread of the English language and English parliamentary institutions, seems the single most important development in British history.

J. A. Cannon