- Ph.D., American History, Brandeis University, 1986
- B.A., History, Colby College, 1977
Early American history (colonial revolutionary and early republic); history of the American West; History of Canada (pre-Confederation)
- The Divided Ground: Indians, Settlers, and the Northern Borderland of the American Revolution (New York: Alfred A. Knopf, 2006).
- Writing Early American History (Philadelphia: University of Pennsylvania Press, 2005). American Colonies (New York: Viking/Penguin, 2001)
- William Cooper's Town: Power and Persuasion on the Frontier of the Early American Republic (New York: Alfred A. Knopf, 1995).
- Liberty Men and Great Proprietors: the Revolutionary Settlement on the Maine Frontier 1760-1820 (Chapel Hill: University of North Carolina Press, 1990).