Barnaby Keeney received his doctorate in history from Harvard in 1939 and taught there until 1941, when after the attack on Pearl Harbor, he enlisted in the Army and served with the 35th Infantry as an officer in charge of an intelligence interpreters team. He was awarded the Bronze Star, the Purple Heart, and the Silver Star, and was discharged a captain.
After the war ended, he studied in Europe before coming to Brown in 1946 as assistant professor of history. He became Dean of the Graduate School in 1949, at the age of 34, and served in this position (with the exception of a leave of absence in 1951 to work for the Central Intelligence Agency) until 1953, when he became Dean of the College. Two years later he was elected president.
Keeney's presidency was another period of remarkable growth: over a dozen major facilities were either acquired by the University or built on its campus, undergraduate enrollment increased by nearly 1,000, the Graduate School nearly tripled in size, and $82 million was raised. Keeney's resignation in 1966 spared the popular president from much of the turmoil that was spreading across college campuses and that was to weaken the presidency of his successor.