With his second novel, The Spy:A Tale of the Neutral Ground, in 1821, James Cooper (the Fenimore would come later) found his true voice and what became his most enduring subject matter: the history of his young nation, born of the clash between Old World and New. Set largely in Westchester County--site of the real-life intrigues of Benedict Arnold and Major John Andre--The Spy traces the conflicting allegiances of rebels and loyalists, with the supposed loyalist spy Harvey Birch (actually in the service of George Washington) finding himself caught up in conflicts between friendship and duty as he moves between the two sides. Washington himself makes an incognito appearance as the mysterious "Mr. Harper." Cooper continued in the same vein with Lionel Lincoln; Or, The Leaguer of Boston (1825), a carefully researched panorama of the coming of the Revolution, complete with detailed depictions of the battles of Lexington and Concord and Bunker Hill.