Cooper's first major success, The Spy, is also his first book set in the period of the American War of Independence. The story starts in 1870 in the area of the country, which was between British-held New York and the Constitutional Army in the Hudson River Valley and upstate New York. The household of mr Wharton and his daughters is visited by the three main protagonists of the story: the mysterious Mr Harper, an American loyalist; Captain Henry Wharton, the son of the hosue and an officer in the British Army; and Mr Harvey Birch, suspected of being a British spy. The differing loyalties of these men are reflected in the differing loyalties of the household they visit with the father trying to remain neutral, his daughter Sarah a supporter of the British and his other daughter Frances supporting the American rebels. The futures of these characters become inextricably linked as they face not only the perils of war, but also the sufferings of the human heart. This is a compelling adventure, which brings to life all the dangers, heartbreak and hope of a society at war with itself.