This collection includes ca. 200 letters to and from Harvey's family, concerning Quakers, the Missouri Compromise, slavery, the depression of 1819-1820. There is also a commonplace book (1819-1820, 1821 Aug.), with observations on a balloon ascension of 2 Aug. 1819 from Vauxhall Gardens in England, slavery, Indians, and descriptions of Washington and Baltimore. There are also journals of trips to Niagara Falls and Canada in 1820 and to the American West, from Baltimore to Louisville and back, with an added description of a voyage around Long Island aboard the Robert Fulton in August 1821.

This collection contains diaries, weather records, and commonplace books of Thomas Thistlewood for the years 1748-1786. His diaries (37 volumes) cover two years in England (in London and in Lincolnshire) and the remaining time in Jamaica (1750-1786). This is a rich source for agricultural, daily routines, slave life, folklore, natural history, medical diagnosis and remedies, the intellectural world of an Anglo-Jamaican, his sex life, and the climatic history of Jamaica. There are also miscellaneous volumes, such as a list of slaves, 1758-1766. Included in the collection is the journal of his nephew, John Thistlewood, 1763-1765, describing his voyage to Jamaica and life on his uncle's plantation.