The 1777 Saratoga campaign helped persuade France to enter a formal alliance with the United States.
The campaign was a British attempt to control the Hudson River Valley and isolate New England from the other colonies. Lieutenant General John Burgoyne led the main British force south from Quebec, while other British movements were intended to support the operation from the west and south.
American forces stopped Burgoyne’s army in the Battles of Saratoga. After the fighting in September and October, Burgoyne surrendered on October 17, 1777. The surrender demonstrated to France that the American cause had a credible chance of defeating Britain.
France had already supplied secret assistance, weapons, and money, but the Saratoga news helped produce an open alliance. The Treaty of Alliance was signed on February 6, 1778, and France soon entered the war against Britain. Saratoga is therefore often called a turning point, although the campaign included several engagements rather than one single battle. The later Yorktown campaign benefited from French military and naval support.