The British, for their part, lacked both a unified command and a clear strategy for winning. With the use of the Royal Navy, the British were able to capture coastal cities, but control of the countryside eluded them. A British sortie from Canada in 1777 ended with the disastrous surrender of a British army at Saratoga. With the coming in 1777 of General von Steuben, the training and discipline along Prussian lines began, and the Continental Army began to evolve into a modern force. France and Spain then entered the war against Great Britain as Allies of the US, ending its naval advantage and escalating the conflict into a world war. The Netherlands later joined France, and the British were outnumbered on land and sea in a world war, as they had no major allies apart from Indian tribes.

Answer this question, if possible (if impossible, reply "unanswerable"): What battle ended a British invasion from the US in the Revolutionary War?
unanswerable