The Patriot organization, the Sons of Liberty, were active in New York in the 1760s and early 1770s following the Stamp Acts. Their activities continued under the Intolerable Acts, and clashes with British troops peaked with the Battle of Golden Hill and the long-running skirmishes over Liberty poles. A Committee of Correspondence was created by Patriots by 1774 to coordinate with like-minded people in the Thirteen Colonies. They demanded what they saw were their rights as Englishmen denied by the preceding laws and lack of representation in the British Parliament. The Committees of Correspondence led to the creation of the New York Provincial Congress, which effectively replaced the British ruling apparatus by 1775. The New York Provincial Congress sent delegates to the Second Continental Congress, where they voted for independence unanimously. The state of New York was created on July 9, 1776.
Soon after, a permanent Committee for Detecting and Defeating Conspiracies was formed. It passed many laws allowing the prosecution of proven or suspected enemies of the rebellion. In the tumultuous times, some people used such laws to settle private grievances and conflicts. After their civil rights were revoked and their property confiscated (see Bill of attainder), many Loyalists sought refuge in British-controlled areas. In 1777, the state required a stringent oath of allegiance from its citizens; those who refused were exiled to British-occupied New York City. The New York Provincial Congress was replaced with the state government with the adoption of the Constitution of New York, 1777.
The Capture of Fort Ticonderoga provided the cannon and gunpowder necessary to force a British withdrawal from the Siege of Boston in 1775. It provided the staging ground for the unsuccessful 1775 invasion of Canada. The first major battle of the American Revolutionary War after independence was declared â€“ and the largest battle of the entire war â€“ was fought in New York at the Battle of Long Island (a.k.a Battle of Brooklyn) in 1776. The Battle of Valcour Island on Lake Champlain took place that year as well. General George Washington withdrew from Manhattan Island, where because of longstanding trade and family ties, there was more support among the people for the British. At the same time, New York became a center for escaping slaves, who had been promised freedom by the British.d
The British made New York City their military and political base of operations in North America for the duration of the conflict. It was consequently the center of attention for Washington's intelligence network. More American combatants died of intentional neglect in the notorious British prison ships of Wallabout Bay than were killed in combat in every battle of the war, combined (see Prisoners in the American Revolutionary War).
The first of two major British armies to surrender during the war was captured by the Continental Army at the Battle of Saratoga in 1777, preventing the British from connecting their forces in Canada with those in New York City. This defeat resulted in France's allying with the revolutionaries. In 1780, Benedict Arnold unsuccessfully attempted to turn West Point over to the British, a move that would have given the British control of the Hudson Valley. As per the Treaty of Paris, the last vestige of British authority in the former Thirteen Colonies â€“ their troops in New York City â€“ departed in 1783. For years afterward the occasion was celebrated as Evacuation Day.
During the revolution, four of the Iroquois nations fought on the side of the British, with the exceptions of the Oneida and the Tuscarora. In 1779, Major General John Sullivan was sent to defeat the Iroquois. The Sullivan Expedition moved northward through the Finger Lakes and Genesee Country, burning all the Iroquois communities and destroying their crops and orchards. Refugees fled to Fort Niagara where they spent the following winter in hunger and misery. Hundreds died of exposure, hunger and disease. After the war, many moved to Canada, where the Crown set aside a land grant to compensate the Iroquois for support during the war, which became known as the Six Nations at Grand River First Nation. Great Britain ceded its land claims to the new United States south of Canada and east of the Mississippi River. In New York, the Iroquois were considered also to have lost their lands, although the US had to negotiate separate treaties with them. At the same time, New York purchased land and made treaties with some of the nations to settle on reservations. Some of the land purchases are the subject of modern-day claims by the individual tribes.