Primary interests include revolutionary and early national America, intellectual and religious history. Author of Beyond Toleration: The Religious Origins of American Pluralism (New York: Oxford UP, 2006) and co-editor of The First Prejudice: Religious Tolerance and Intolerance in Early America (UPenn, Pub. date: Oct. 2010). Current research focuses on the controversies over public education in 19th-century America and the history of the religious clauses First Amendment. He is also writing a short history of religious tolerance and intolerance in the United States.