American Revolution, also called United States War of Independence or American Revolutionary War, (1775–83), insurrection by which 13 of Great Britain’s North American colonies won political independence and went on to form the United States of America. The war followed more than a decade of growing estrangement between the British crown and a large and influential segment of its North American colonies that was caused by British attempts to assert greater control over colonial affairs after having long adhered to a policy of salutary neglect. Until early in 1778 the conflict was a civil war within the British Empire, but afterward it became an international war as France (in 1778) and Spain (in 1779) joined the colonies against Britain. Meanwhile, the Netherlands, which provided both official recognition of the United States and financial support for it, was engaged in its own war against Britain. From the beginning, sea power was vital in determining the course of the war, lending to British strategy a flexibility that helped compensate for the comparatively small numbers of troops sent to America and ultimately enabling the French to help bring about the final British surrender at Yorktown.
