Richard W. Leopold, a prominent diplomatic historian whose teaching and scholarship guided students and colleagues during an illustrious career, died of natural causes November 23, 2006, in Evanston, Illinois. He was 94.

Among the hundreds of former students identifying Leopold as a mentor who profoundly affected their lives are former Senator George McGovern, former Representative Richard Gephardt, Representative Jim Kolbe, former assistant secretary of state Phyllis Elliot Oakley, historian John Morton Blum, journalist Georgie Anne Geyer, and television and motion picture producer/writer/director Garry Marshall. Kolbe wrote, "I used to say with great pride that I learned American diplomatic history at the feet of one of the greatest scholars in the United States—Dick Leopold. I knew that statement would not be challenged in or out of academic circles. . . . [He] believed that being a teacher and a mentor was a lifetime commitment, and for those who responded, it became a lifetime of friendship." McGovern noted, "I believe that every thoughtful student who studied under Professor Leopold's direction would agree that this country has produced no more dedicated and competent professor. He has not only mastered his field but he has had a lifetime passion to convey his knowledge and insight to his students." Marshall recalled his difficulty answering long essay questions in final exam blue books and how Leopold "allowed me to answer with dialogue scenes rather than prose writing and graded me on content rather than style. It helped me tremendously and I think my early Bismarck dialogue aided me in writing sitcoms and movies for a living."
The second son of Harry Leopold Sr. and Ethel Kimmelstiel, Richard Leopold was born on January 6, 1912, on the upper west side of Manhattan. He attended the Franklin School before enrolling in 1926 at Phillips Exeter Academy, where he graduated cum laude in 1929. He then went on to Princeton University, graduating with highest honors and Phi Beta Kappa in 1933.

After Princeton he pursued graduate study at Harvard under the tutelage of Arthur M. Schlesinger Sr., receiving a master's degree in 1934 and a PhD in 1938. Leopold's doctoral dissertation became his first book, Robert Dale Owen: A Biography (1940), which won the American Historical Association's John H. Dunning Prize as the best book on any subject relating to United States history.

During World War II, he was commissioned as a naval officer and worked at the Office of Naval Records and Library in Washington, where he devised a unique system—used long thereafter—for organizing materials relating to ongoing naval operations. After the war, he returned to Harvard for two years before joining the Northwestern University faculty in 1948. Over the subsequent three decades there, Leopold was instrumental in Northwestern's successful effort to build one of the finest collection of American history scholars ever assembled at a single institution of its size. In addition to Leopold, the 1950s roster included Ray A. Billington, Arthur S. Link, and Clarence L. Ver Steeg. Leopold and Link became especially close collaborators, producing the Problems in American History series, among many other works. In addition to hundreds of articles, Leopold also wrote Elihu Root and the Conservative Tradition (1954) and The Growth of American Foreign Policy: A History (1962), which remained a seminal treatise in United States diplomatic history for more than a decade after its first publication. He became the William Smith Mason Professor of History in 1963.

At the height of the Vietnam War protests in 1968, Leopold led the successful effort to prevent Northwestern from dismantling its Naval ROTC program, even though virtually all other comparable academic institutions were doing so. He made a three-fold case in favor of retaining the program. First, it benefited the nation. He was concerned about the potential need to mobilize quickly in times of war; he was also concerned about a military whose officer ranks came exclusively from the service academies and the limited perspectives they offered. Second, the program benefited the university. He noted the many noteworthy program participants who had enriched the university and who would have been unable to attend Northwestern without the NROTC's financial support. Third, he argued that NROTC helped the students who participated. He was unmoved by those who argued that the program itself somehow proved the academy's support for a controversial war or "the teaching of killing." His faculty address turned the tide of the debate in favor of retaining the program. "We do not ban the teaching of nuclear physics because someone might make a bomb," he said, "[and] we do not avoid the study of Marxism because the student might become a Communist." Many of the program's graduates went on to become career officers; some rose to the rank of admiral.

In 1969, Leopold was tapped to head an independent investigation into Francis L. Loewenheim's charges against the Franklin D. Roosevelt Presidential Library. Loewenheim claimed that the FDR Library staff had withheld certain documents in connection with his research and further asserted that the American Historical Association, Organization of American Historians, and National Archives had thereafter covered up his resulting charges. After a year-long investigation, the joint AHA-OAH committee that Leopold chaired issued a 447-page report, Final Report of the Joint AHA-OAH Ad Hoc Committee to Investigate the Charges Against the Franklin D. Roosevelt Library and Related Matters (1970). Contrary to Loewenheim's allegations, the report concluded that there had been no conspiracy and that the professional bodies charged with investigating the original complaint had simply been ill-equipped to deal with the vicious and unprecedented assault that Loewenheim and his lawyer had launched against a group of academics.

Leopold served on numerous governmental advisory committees, including those for the Secretary of the Navy, State Department, Army, Marine Corps, Atomic Energy Commission, CIA, and Library of Congress. He was also a member of the editorial advisory committee for The Papers of Woodrow Wilson and of the board of directors for the Harry S. Truman Library Institute. He was president of the Society for Historians of American Foreign Relations in 1970 and of the Organization of American Historians in 1976.

In 1984, Leopold's former doctoral students established the OAH's Richard W. Leopold Prize, which is awarded biannually. In 1990, former students, colleagues, and friends established the annual Richard W. Leopold Lectureship at Northwestern in his honor. This year's lecturer was Samantha Power. In 1997, more than 230 former students collectively endowed the Richard W. Leopold Professorship in American history at Northwestern.

He is survived by a nephew, John P. Leopold, who lives in Centennial, Colorado. A former student, Steven J. Harper, has written Leopold's biography, which Northwestern University Press has tentatively scheduled for publication in early 2008.

—Steven J. Harper
Kirkland & Ellis LLP