- May 14, 1927 – At dedication ceremonies for the John W. Weeks Memorial Bridge, Henry Hornblower, representing the firm of Hornblower & Weeks, formally presents the bridge to Harvard. The University in turn presents the footbridge across the Charles to the Commonwealth of Massachusetts.
- May 8, 1939 – The Littauer Center of Public Administration (predecessor of the John F. Kennedy School of Government) is dedicated.
- May 18-29, 1942 – About 50 newspaper editors from across the nation convene in the Faculty Club Library for an “Institute on War Problems,” sponsored by the Nieman Foundation (for journalism). In on- and off-the-record talks, participants learn helpful cues for interpreting wartime news on a global scale.
- May 7, 1964 – A crowd of some 1,500, including many undergraduates, gathers beneath the sycamores along the Charles chanting, “We shall not be underpassed,” thus protesting plans of the Metropolitan District Commission for a Memorial Drive underpass that would destroy most of the venerable trees and, many fear, seriously compromise the quality of life in Cambridge.
– From the Harvard Historical Calendar, a database compiled by Marvin Hightower