Here are some of his notable works:
* The Rise and Fall of the French Revolution (1969): This is his most famous work, considered a landmark study of the French Revolution. It provides a comprehensive analysis of the revolution's origins, development, and eventual decline.
* The Intellectual History of Modern Europe (1972): A comprehensive and insightful overview of European intellectual history from the Renaissance to the present.
* The City of Man: Europe, 1800-1900 (1973): Explores the major themes and movements of European history during the 19th century.
* European History: A Survey (1975): A textbook covering the major events and trends of European history.
* The New French Revolution (1988): Examines the political and social changes in France during the 20th century, particularly the rise of the Fifth Republic.
* The French Revolution: A First-Hand Account (1989): A compilation of primary source documents, offering a glimpse into the events of the French Revolution through the words of those who lived it.
* The Enlightenment and the French Revolution (1993): A detailed exploration of the intellectual and political connections between the Enlightenment and the French Revolution.
In addition to these books, Wagar also published numerous articles and essays on a wide range of historical topics.
He was a prolific writer who made significant contributions to the understanding of European history, especially the Enlightenment and the French Revolution. His work is still widely read and studied today.