The American Revolutionary War (1775–1783), also known as the American War of Independence, was, at least initially, a civil war between the Kingdom of Great Britain and thirteen British colonies on the North American continent (as well as some naval conflict). The war was the culmination of the political American Revolution, whereby the colonists overthrew Royalist rule. In 1775, Revolutionaries seized control of each of the thirteen colonial governments, set up the Second Continental Congress, and formed a Continental Army. The following year, they formally declared their independence as a new nation, the United States of America. From this time on, other European nations which rivalled Britain as colonial powers provided support for the rebels, at first secretly, later openly. Meanwhile, Native Americans and African Americans served on both sides.

Throughout the war, the British were able to use their naval superiority to capture and occupy coastal cities, but control of the countryside (where 90% of the population lived) largely eluded them due to their relatively small land army. In early 1778, shortly after an American victory at Saratoga, France signed treaties of alliance with the new nation, and declared war on Britain that summer; Spain and the Netherlands also went to war with Britain over the next two years. French involvement proved decisive, with a French naval victory in the Chesapeake leading to the surrender of a British army at Yorktown in 1781. The Treaty of Paris in 1783 ended the war and recognized the sovereignty of the United States over the territory bounded by what is now Canada to the north, Florida to the south, and the Mississippi River to the west.