Beginning with his college life as an undergraduate at Harvard (1905-1906), Morley's diaries continue through his earliest travels and explorations of Central America (1907-1944), with information on the study of Mayan hieroglyphs, publications, the study of Central American ruins, and the manners and customs of the jungle Indians. Five volumes are devoted to four separate archaeological expeditions: Copan expedition (1937), Uxmal expedition (1941-1942), Central American expedition (1944), and Guatemala and Honduras expedition (1947). Formal and detailed field notes form the bulk of Morley's archaeological work. There are no diaries for 1908-1911, 1913, 1926-1930, 1933-1936, 1938-1940, and 1943.