sentences:  He attended Swarthmore College, where he was awarded a Bachelor of Arts degree during 1948, having had an interruption of three years while he served in the United States Merchant Marine during World War II, serving aboard ship as a radio operator.He did his graduate work at Harvard University, earning a Master of Arts degree during 1949 and was awarded his Ph.D. during 1953.His doctoral dissertation, titled "Revolution and Decline in Jamaica, 1830–1865" addressed 19th-century history and economics of Jamaica.