American Revolutionary War: A British fleet defeated American ships at the Battle of Valcour Island on Lake Champlain, but gave American forces enough time to prepare their defenses for the Saratoga campaign.

The American Revolutionary War, also known as the Revolutionary War or American War of Independence, was the armed conflict that comprised the final eight years of the broader American Revolution, in which American Patriot forces organized as the Continental Army and commanded by George Washington defeated the British Army. The conflict was fought in North America, the Caribbean, and the Atlantic Ocean. The war's outcome seemed uncertain for most of the war. But Washington and the Continental Army's decisive victory in the Siege of Yorktown in 1781 led King George III and the Kingdom of Great Britain to negotiate an end to the war in the Treaty of Paris two years later, in 1783, in which the British monarchy acknowledged the independence of the Thirteen Colonies, leading to the establishment of the United States as an independent and sovereign nation.

The Battle of Valcour Island, also known as the Battle of Valcour Bay, was a naval engagement that took place on October 11, 1776, on Lake Champlain. The main action took place in Valcour Bay, a narrow strait between the New York mainland and Valcour Island. The battle is generally regarded as one of the first naval battles of the American Revolutionary War, and one of the first fought by the Continental Navy. Most of the ships in the American fleet under the command of Benedict Arnold were captured or destroyed by a British force under the overall direction of General Guy Carleton. However, the American defense of Lake Champlain stalled British plans to reach the upper Hudson River valley.

Lake Champlain is a large natural freshwater lake in North America. With a length of 107 mi (172 km) and surface area over 500 sq mi (1,295 km²), it lies mostly between the U.S. states of New York and Vermont, but also extends north into the Canadian province of Quebec.