The British plan to the end of the war in 1777 ended in a large British army was forced to surrender at what?

The British surrender at Saratoga, NY (17 October 1777) is considered the turning point of the American Revolution. Saratoga was actually two battles, fought eighteen days apart in September and October 1777. On 19 September, British General John Burgoyne achieved a small, but costly victory over American forces commanded by Horatio Gates and Benedict Arnold, with Burgoyne attacking the Americans again on 7 Oct. However this time the British were defeated and forced to retreat. Burgoyne surrendered ten days later, and the American victory convinced the French government to formally recognize the American government and enter the war as their ally.

Saratoga