As an entertainer for over twenty years, Jon is known as the NFL's “Magic Man" and is respectfully referred to as the "Entertainer's Entertainer." He also has performed personally for Jason Statham, Nicholas Cage, Garth Brooks, Magic Johnson, the entire New England Patriots football team, Joe Montana and Dan Marino.

Reflecting his interdisciplinary training in American Studies, which combined the fields of history, literature, and economics, Professor Kennedy's scholarship is notable for its integration of economic and cultural analysis with social and political history. His 1970 book, Birth Control in America: The Career of Margaret Sanger, embraced the medical, legal, political, and religious dimensions of the subject and helped to pioneer the emerging field of women's history. Over Here: The First World War and American Society (1980) used the history of American involvement in World War I to analyze the American political system, economy, and culture in the early twentieth century. Freedom From Fear: The American People in Depression and War (1999) recounts the history of the United States in the two great crises of the Great Depression and World War II.