The Invasion of Quebec (June 1775 October 1776, French: Invasion du Qubec) was the first major military initiative by the newly formed Continental Army during the American Revolutionary War. The objective of the campaign was to seize the Province of Quebec (part of modern-day Canada) from Great Britain, and persuade French-speaking Canadiens to join the revolution on the side of the Thirteen Colonies. One expedition left Fort Ticonderoga under Richard Montgomery, besieged and captured Fort St. Johns, and very nearly captured British General Guy Carleton when taking Montreal. The other expedition, under Benedict Arnold, left Cambridge, Massachusetts and traveled with great difficulty through the wilderness of Maine to Quebec City. The two forces joined there, but they were defeated at the Battle of Quebec in December 1775.

Montgomery's expedition set out from Fort Ticonderoga in late August, and in mid-September began besieging Fort St. Johns, the main defensive point south of Montreal. After the fort was captured in November, Carleton abandoned Montreal, fleeing to Quebec City, and Montgomery took control of Montreal before heading for Quebec with an army much reduced in size by expiring enlistments. There he joined Arnold, who had left Cambridge in early September on an arduous trek through the wilderness that left his surviving troops starving and lacking in many supplies and equipment.

These forces joined before Quebec City in December, and they assaulted the city in a snowstorm on the last day of the year. The battle was a disastrous defeat for the Continental Army; Montgomery was killed and Arnold wounded, while the city's defenders suffered few casualties. Arnold then conducted an ineffectual siege on the city, during which successful propaganda campaigns boosted Loyalist sentiments, and General David Wooster's blunt administration of Montreal served to annoy both supporters and detractors of the Americans.

The British sent several thousand troops under General John Burgoyne, including Hessian mercenaries, to reinforce the province in May 1776. General Carleton then launched a counter-offensive, ultimately driving the smallpox-weakened and disorganized Continental forces back to Fort Ticonderoga. The Continental Army, under Arnold's command, hindered the British advance sufficiently that an attack could not be mounted on Fort Ticonderoga in 1776. The end of the campaign set the stage for Burgoyne's 1777 campaign in the Hudson River valley.

The American Revolutionary War (April 19, 1775 – September 3, 1783), also known as the Revolutionary War or American War of Independence, secured a United States of America independent from Great Britain. Fighting began on April 19, 1775, followed by the Declaration of Independence on July 4, 1776. The American Patriots were supported by France and Spain, conflict taking place in North America, the Caribbean, and Atlantic Ocean. It ended on September 3, 1783 when Britain accepted American independence in the Treaty of Paris, while the Treaties of Versailles resolved separate conflicts with France and Spain.Established by Royal charter in the 17th and 18th centuries, the American colonies were largely autonomous in domestic affairs and commercially prosperous, trading with Britain and its Caribbean colonies, as well as other European powers via their Caribbean entrepôts. After British victory in the Seven Years' War in 1763, tensions arose over trade, colonial policy in the Northwest Territory and taxation measures, including the Stamp Act and Townshend Acts. Colonial opposition led to the 1770 Boston Massacre and 1773 Boston Tea Party, with Parliament responding by imposing the so-called Intolerable Acts.

On September 5, 1774, the First Continental Congress drafted a Petition to the King and organized a boycott of British goods. Despite attempts to achieve a peaceful solution, fighting began with the Battle of Lexington on April 19, 1775 and in June Congress authorized George Washington to create a Continental Army. Although the "coercion policy" advocated by the North ministry was opposed by a faction within Parliament, both sides increasingly viewed conflict as inevitable. The Olive Branch Petition sent by Congress to George III in July 1775 was rejected and in August Parliament declared the colonies to be in a state of rebellion.

Following the loss of Boston in March 1776, Sir William Howe, the new British commander-in-chief, launched the New York and New Jersey campaign. He captured New York City in November, before Washington won small but significant victories at Trenton and Princeton, which restored Patriot confidence. In summer 1777, Howe succeeded in taking Philadelphia, but in October a separate force under John Burgoyne was forced to surrender at Saratoga. This victory was crucial in convincing powers like France and Spain an independent United States was a viable entity.

France provided the US informal economic and military support from the beginning of the rebellion, and after Saratoga the two countries signed a commercial agreement and a Treaty of Alliance in February 1778. In return for a guarantee of independence, Congress joined France in its global war with Britain and agreed to defend the French West Indies. Spain also allied with France against Britain in the Treaty of Aranjuez (1779), though it did not formally ally with the Americans. Nevertheless, access to ports in Spanish Louisiana allowed the Patriots to import arms and supplies, while the Spanish Gulf Coast campaign deprived the Royal Navy of key bases in the south.

This undermined the 1778 strategy devised by Howe's replacement, Sir Henry Clinton, which took the war into the Southern United States. Despite some initial success, by September 1781 Cornwallis was besieged by a Franco-American force in Yorktown. After an attempt to resupply the garrison failed, Cornwallis surrendered in October, and although the British wars with France and Spain continued for another two years, this ended fighting in North America. In April 1782, the North ministry was replaced by a new British government which accepted American independence and began negotiating the Treaty of Paris, ratified on September 3, 1783.