The President Who Sent Bones to Confront a Scientist
Thomas Jefferson was obsessed with proving that American wildlife was not inferior to European species, opposing a French theory of "American degeneracy." To prove his point, Jefferson ordered a massive mastodon skeleton and sent a giant, stuffed bull moose directly to the French naturalist's office.
The Theory of American Degeneracy
In the eighteenth century, one of Europe's most influential scientific figures, the French naturalist Georges-Louis Leclerc, Comte de Buffon, published a sweeping multivolume work on natural history. In it, Buffon advanced a theory that sparked intense debate across the Atlantic: the hypothesis of New World degeneracy. Buffon argued that the climate of the Americas—which he characterized as excessively cold, humid, and swampy—stifled the healthy development of living organisms. As a consequence, he claimed, American animal species were systematically smaller, weaker, and less diverse than their European counterparts, and European animals transported to the Americas would inevitably shrink and degenerate over generations.
Buffon's ideas were widely read and accepted among European intellectuals, and other European writers soon expanded the concept to suggest that native human populations, and even European colonists living in the Americas, suffered from intellectual and physical decline. To early American leaders trying to establish their young nation's international standing, Buffon's theory was not merely an abstract scientific dispute. It was a direct insult to the viability, natural wealth, and future of the American continent. For Thomas Jefferson, disproving this theory became both a scientific mission and a matter of national honor.
A Defense in Data: Notes on the State of Virginia
Jefferson confronted the degeneracy thesis head-on in his only published full-length book, Notes on the State of Virginia. Written in response to queries from a French diplomat regarding the geography, resources, and society of Virginia, the work allowed Jefferson to systematically dismantle Buffon's assertions with empirical evidence. Jefferson compiled detailed comparative tables listing the weights of North American mammals alongside those of European quadrupeds, aiming to demonstrate that American species were equal to, and frequently larger than, their Old World relatives.
In his writings, Jefferson challenged Buffon's reasoning on multiple fronts. He pointed out that Buffon had never visited North America and relied on incomplete or biased reports from travelers. Jefferson argued that moisture and climate varied widely across the continent and did not produce stunted life. To support his claims, Jefferson cited animals such as the beaver, the bear, and the North American elk, contrasting their documented dimensions against European species. However, Jefferson knew that printed tables alone might not fully persuade European naturalists who still held sway over scientific opinion.
The Expedition for a New England Moose
While serving as the American minister to France in Paris during the 1780s, Jefferson decided that tangible, physical proof was necessary to settle the debate with Buffon in person. Jefferson recognized that the moose, the largest member of the deer family, was the ultimate living refutation of the claim that American quadrupeds were diminutive. He wrote to colleagues and friends in New England, requesting that they procure a complete, full-grown bull moose, preserve its skin, bones, and antlers, and ship the entire specimen across the Atlantic to France.
Acquiring such a specimen proved to be a difficult and expensive undertaking. A team in New Hampshire eventually tracked down and shot a large moose, prepared its remains, and packed the skeleton, pelt, and horns for transport. When the shipment finally arrived in Paris, Jefferson arranged to have the specimen delivered to Buffon's residence at the King's Garden. Although the skin had lost much of its hair during the long journey, the sheer stature of the skeleton and the massive antlers provided indisputable physical evidence that North American forests supported towering fauna.
Unearthing the Prehistoric Past
Jefferson's quest to defend American nature extended into the realm of paleontology. During the late eighteenth and early nineteenth centuries, laborers and explorers were beginning to unearth massive fossilized bones across North America, most notably at Big Bone Lick in Kentucky. These enormous remains, which belonged to extinct mastodons and mammoths, provided Jefferson with further evidence that the North American continent had supported creatures of immense scale, far exceeding the size of modern European animals.
Jefferson was an avid fossil collector and an enthusiastic scholar of natural history, eventually serving as president of the American Philosophical Society for nearly two decades. In 1797, he presented a paper to the society describing fossil bones found in western Virginia, which he designated as Megalonyx. Although Jefferson initially hypothesized that the large claw belonged to an enormous, lion-like predator, later scientific analysis identified the creature as an extinct giant ground sloth. Nevertheless, Jefferson's work on the fossil cemented his reputation as a pioneer of early American vertebrate paleontology.
Fossils and the Western Frontier
Jefferson's fascination with large fauna directly influenced his presidential policies, particularly regarding the exploration of the American West. At the time, the concept of biological extinction was still controversial and not universally accepted. Jefferson believed in a balanced natural order and reasoned that nature would not permit an entire species to disappear completely. Consequently, he thought it possible that living mastodons and other prehistoric giants might still roam the uncharted wilderness of the interior continent.
When Jefferson commissioned Meriwether Lewis and William Clark to lead the Corps of Discovery across the Louisiana Territory to the Pacific Ocean, his detailed instructions included studying the flora, fauna, and geology of the region. He specifically instructed the explorers to look out for unknown animal species and any signs of mammoth remains. Later in his presidency, Jefferson even financed William Clark to return to Big Bone Lick to excavate fossil specimens, filling rooms in the White House with fossilized teeth and bones to study and distribute to scientific collections in the United States and Europe.
The Intersection of Science and Nation-Building
Jefferson's confrontation with European naturalists over the degeneracy thesis highlights the unique intersection of science and national identity in the early United States. In the decades following the American Revolution, establishing the legitimacy of the new republic required more than political treaties and military defense; it required defending the ecological vitality and potential of the land itself. By championing American natural history, Jefferson sought to place American scholarship on equal footing with European academies.
Though modern biology and paleontology have since discarded both the theory of degeneracy and the belief that mastodons still walked the continent, Jefferson's efforts had lasting impacts on American science. His insistence on direct empirical measurement, field collection, and systematic comparison helped stimulate the development of museums, scientific societies, and natural history research in the United States. His moose and mastodon campaigns remain famous examples of how early American leaders used the natural world to assert their nation's stature on the world stage.
Key takeaways
•Thomas Jefferson actively fought the 'American degeneracy' theory, which claimed New World wildlife and people were smaller and weaker due to climate.
•In 'Notes on the State of Virginia', Jefferson published comparative weight tables of American and European quadrupeds to disprove European claims.
•While minister to France, Jefferson had a large New England bull moose carcass and skeleton shipped to Paris to confront the naturalist Count Buffon with physical proof.
•Jefferson's passion for natural history led him to study mastodon and Megalonyx fossils, shaping early American paleontology and expeditions like Lewis and Clark's.