(Definition of harp on (about sth) from the Cambridge Advanced Learners Dictionary & Thesaurus Â© Cambridge University Press).
Battle of Saratoga. In late September and during the first week of October 1777, Gate's American army was positioned between Burgoyne's army and Albany. On October 7, Burgoyne took the offensive. The troops crashed together south of the town of Saratoga, and Burgoyne's army was broken. In mop-up operations 86 percent of Burgoyne's command was captured.
The battle of Saratoga took place on the fields of upstate New York, nine miles south of the town of Saratoga. In accordance with British plans, General John Burgoyne was attempting to invade New England from Canada with the goal of isolating New England from the rest of the United States.