Not to the Swift: The Old Isolationists in the Cold War Era (Lewisburg, Pa.: Bucknell University Press, 1979). The Diplomacy of Frustration: The Manchurian Crisis of 1931-1933 as Revealed in the Papers of Stanley K. Hornbeck (Hoover Archival Documentaries; Stanford, Calif.: Hoover Institution Press, 1981).
The Presidencies of James A. Garfield and Chester A. Arthur (American Presidency Series; Lawrence, Kansas: Regents Press of Kansas, 1981).
When the Wicked Rise: American Opinion-Makers and the Manchurian Crisis of 1931-1933 (Lewisburg, Pa.: Bucknell University Press, 1984).
Anti-Intervention: A Bibliographical Introduction to Isolationism and Pacifism from World War I to the Early Cold War (New York: Garland, 1987).
In Danger Undaunted: The Anti-Interventionist Movement of 1940-1941 as Revealed in the Papers of the America First Committee (Hoover Archival Documentaries; Stanford, Calif.: Hoover Institution Press, 1990).
From Isolation to War, 1931-1941 (American History Series; 4th ed., 2015, 3rd ed., 2003; Arlington Heights, Ill.: Harlan Davidson, 2002; 2nd ed., 1991; all with John E. Wilz as co-author).
The Battle Against Intervention, 1939-1941 (Anvil Series; Malabar, Fla.: Krieger, 1997).
Storm on the Horizon: The Challenge to American Intervention, 1939-1941 (Lanham, Md.: Rowman and Littlefield, 2000).
The New Deal (Anvil series; Malabar, Fla.: Krieger, 2003)
Debating Franklin D. Roosevelt’s Foreign Policies (Lanham, Md. Rowman and Littlefield, 2005; with Mark A. Stoler as co-author)
Nothing Less Than War: A New History of American Entry into World War I, 1914-1917 (Lexington, University Press of Kentucky, 2011); alternate selection of History and Military book clubs
Articles for professional journals and reference books