Until the end of the Seven Years' War in 1763, few colonists in British North America objected to their place in the British Empire. Colonists in British America reaped many benefits from the British imperial system and bore few costs for those benefits. Indeed, until the early 1760s, the British mostly left their American colonies alone. The Seven Years' War (known in the United States as the French and Indian War) changed everything. Although Britain eventually achieved victory over France and its allies, victory had come at great cost. A staggering war debt influenced many British policies over the next decade. Attempts to raise money by reforming colonial administration, enforcing tax laws, and placing troops in America led directly to conflict with colonists. By the mid-1770s, relations between Americans and the British administration had become strained and acrimonious.
The first shots of what would become the war for American independence were fired in April 1775. For some months before that clash at Lexington and Concord, patriots had been gathering arms and powder and had been training to fight the British if that became necessary. General Thomas Gage, commander of British forces around Boston, had been cautious; he did not wish to provoke the Americans. In April, however, Gage received orders to arrest several patriot leaders, rumored to be around Lexington. Gage sent his troops out on the night of April 18, hoping to catch the colonists by surprise and thus to avoid bloodshed. When the British arrived in Lexington, however, colonial militia awaited them. A fire fight soon ensued. Even so, it was not obvious that this clash would lead to war. American opinion was split. Some wanted to declare independence immediately; others hoped for a quick reconciliation. The majority of Americans remained undecided but watching and waiting.
In June 1775, the Continental Congress created, on paper, a Continental Army and appointed George Washington as Commander. Washington's first task, when he arrived in Boston to take charge of the ragtag militia assembled there, was to create an army in fact. It was a daunting task with no end of problems: recruitment, retention, training and discipline, supply, and payment for soldiers' services were among those problems. Nevertheless, Washington realized that keeping an army in the field was his single most important objective.
During the first two years of the Revolutionary War, most of the fighting between the patriots and British took place in the north. At first, the British generally had their way because of their far superior sea power. Despite Washington's daring victories at Trenton and Princeton, New Jersey, in late 1776 and early 1777, the British still retained the initiative. Indeed, had British efforts been better coordinated, they probably could have put down the rebellion in 1777. But such was not to be. Patriot forces, commanded by General Horatio Gates, achieved a significant victory at Saratoga, New York, in October 1777. Within months, this victory induced France to sign treaties of alliance and commerce with the United States. In retrospect, French involvement was the turning point of the war, although that was not obvious at the time.
Between 1778 and 1781, British military operations focused on the south because the British assumed a large percentage of Southerners were loyalists who could help them subdue the patriots. The British were successful in most conventional battles fought in that region, especially in areas close to their points of supply on the Atlantic coast. Even so, American generals Nathanael Greene and Daniel Morgan turned to guerrilla and hit-and-run warfare that eventually stymied the British. By 1781, British General Lord Charles Cornwallis was ordered to march into Virginia to await resupply near Chesapeake Bay. The Americans and their French allies pounced on Cornwallis and forced his surrender.
Yorktown was a signal victory for the patriots, but two years of sporadic warfare, continued military preparations, and diplomatic negotiations still lay ahead. The Americans and British signed a preliminary peace treaty on November 30, 1782; they signed the final treaty, known as the Peace of Paris, on September 10, 1783. The treaty was generally quite favorable to the United States in terms of national boundaries and other concessions. Even so, British violations of the agreement would become an almost constant source of irritation between the two nations far into the future.