Pusey was President of Harvard from 1953 to 1971 and gained national prominence for his defense of universities and academic freedom during the McCarthy Era. Under his administration, Harvard's endowment grew from $304 million to more than $1 billion, and many new buildings were constructed. Toward the end of his term, Pusey found himself once again beset by controversy - this time, from within. Fueled by burning issues such as the Vietnam War, civil rights, economic justice, and the women’s movement, student activism escalated to the boiling point by the late 1960s at Harvard and elsewhere. On April 9, 1969, radical students ejected administrators from University Hall and occupied the building to protest Harvard’s ROTC program and University expansion into Cambridge and Boston neighborhoods. Early the next morning, many protesters sustained injuries requiring medical treatment after Pusey called in outside police to remove the demonstrators. In response, other students voted to strike and boycott classes. The University almost closed early. The gateway had just opened onto the greatest period of sustained upheaval in Harvard history. Pusey defended his actions until the end of his long life, but the events of April 1969 undoubtedly shortened his presidency. In February 1970, he made a surprise announcement: he was retiring two years early. Pusey left Harvard in June 1971 to become the second president of New York’s Andrew W. Mellon Foundation. Pusey earned an A.B. degree from Harvard in 1928, an M.A. in 1932, and a Ph.D. in 1937, specializing in ancient history. Before becoming President of Harvard, he taught history at Lawrence College, Scripps College, and Wesleyan University, and served as president of Lawrence College.