His most recent classes have been about slavery and antislavery in the revolutionary period (1760s–1820s) and about the history of American families. He is most interested in social and cultural history and in the debates of the postrevolutionary period over what kind of nation or society the United States should be. His first book, Beyond the Farm: National Ambitions in Rural New England (2008), was about ambition among New England farm families. His current book project, Avenging the People: Andrew Jackson, the Rule of Law, and the American Nation (2017) centers on the problem of vengeance—extra-legal violence and punishment—and a man who built his life around its pursuit: Andrew Jackson.