Keith Stewart Thompson in American Scientist:
In 1781, in the midst of the American Revolutionary War, the British army rousted Thomas Jefferson from his home in Monticello. Politically unpopular, he retired from the governorship of Virginia and threw himself into writing. The result was his only book, Notes on the State of Virginia (1785), in which, among other topics, he famously defended his country against those Europeans who said that the Americas (North, South and Central) were unhealthy places populated by lesser animals and plants, compared with those of the Old World, and inhabited by peoples who were similarly weak and degenerate.
The immediate source of these libels was Histoire naturelle, générale et particulière, written in 44 quarto volumes between 1749 and 1809 by Georges-Louis Leclerc, Comte de Buffon, and his associates. A product of the age of French encyclopedists, Histoire naturelle pulled together a vast array of facts about natural history around the world. It was also the vehicle for Buffon’s many ideas about the history of the Earth and the organisms that inhabit it. Buffon had never been to the New World, but that did not prevent him from damning it. His critique carried an importance far greater than its questionable scientific value. Anything that lessened the public opinion of America—awash in foreign debt, at war with a global superpower, supplicant to the thrones of France and Spain—had political significance. Buffon had to be answered.