Jefferson’s main piece of writing, it originated as letters in response to questions from François Barbé-Marbois, a French diplomat. In this work, Jefferson explores a wide variety of topics from the climate, terrain and waterways to colleges, commerce, politics, and history. Such a variety of topics defies easy summary. The work can be subdivided into to areas: natural and civil history.

His reasons for writing about natural history stem from the popular European perception of North American inferiority. European biologists presented North America as inferior because they lacked large animals and their climate and terrain reduced virility in both animals and humans alike. Jefferson’s findings successfully demonstrated the fecundity of American plants and animals as well as presenting important information about Virginia’s civil history, slavery, husbandry, vices of the cities, and the Virginian Constitution.