In 1777, as part of a grand strategy to end the war, the British sent an invasion force from Canada to seal off New England, which the British perceived as the primary source of agitators. In a major case of mis-coordination, the British army in New York City went to Philadelphia which it captured from Washington. The invasion army under
Burgoyne waited in vain for reinforcements from New York, and became trapped in northern New York state. It surrendered after the
Battle of Saratoga in October 1777