Thomas Jefferson is best known for expressing in words the justification for American independence. But Jefferson the politician and statesman coexisted with Jefferson the scientist. The combination led Jefferson to invest a great amount of time and energy in debunking a popular European conceit—that America was a degenerate place. American degeneracy allegedly was evident in its weak and stunted flora, fauna and people.

Jefferson’s effort to illustrate the complete biological equality of the New and Old Worlds went beyond mere pride in his home continent—he and other founders believed that a successful rebuttal was necessary to ensure the growth and prosperity of their new country. The fight was important enough to have been noted in a eulogy at Jefferson’s funeral in 1826 by New York Senator Samuel Latham Mitchill, who called the antidegeneracy campaign the equivalent of proclaiming independence a second time. And one piece of concrete evidence that Jefferson thought he needed to win the day was a specimen of an American moose.

Buffon’s Claims of Degeneracy
The European belief in American inferiority originated to a great extent with the most influential natural historian of the 18th century. Georges-Louis Leclerc—known as Count Buffon—was arguably the most famous scientist of his day. He wrote the 36-volume Natural History, still regarded as a masterpiece. His goal was to provide “the exact description and the true history of each thing” on earth. Natural History was a huge success, became the talk of the salons of Paris and was translated into English, German and Dutch.

In volumes 9 and 14 of Natural History, ­Buffon argued that most animals—and people—in the Americas were lesser than in the Old World. The echoes of that conceit still reverberate. In his 2005 book The American Enemy: The History of French Anti-American­ism, Philippe Roger argues that the French attitude “was born and proposed in philosophical circles” that revolved around Buffon.

The explanation: colder and more humid conditions had somehow brought about this state. The exceptions: Buffon was willing to cede that frogs—which were said to weigh up to 37 pounds—and insects were larger in America. But these examples only reinforced the degeneracy rule, as what could be more repugnant than a massive frog or mosquito?

Buffon laid out four related claims. Animals found in both hemispheres were smaller and feebler in the New World. Animals that lived only in the New World were somehow lesser than comparative species found only in the Old World. The New World had fewer species. And, finally, the New World actually caused degeneration in livestock.

Readers of Natural History were told that sheep raised in the New World were “commonly more meagre, and their flesh less juicy and tender than those of Europe.” They learned that the New World had but half the species of the Old and that they were a motley lot. Buffon even claimed that most American birds could not sing, a falsehood based on a line in a 1769 ­Oliver Goldsmith poem, “The Deserted Village,” about the Georgia wilderness: “Those matted woods, where birds forget to sing.”

After dispensing with the animals, Buffon moved to the indigenous peoples. American Indians had “no vivacity, no activity of mind.” They were, Buffon claimed, “a kind of weak automaton, incapable of improving or seconding [Nature’s] intentions.” Thus were Native Americans responsible for the poor show of the rest of the New World’s occupants. Having failed to tame nature, the natives had neglected to produce an environment conducive to forming healthier specimens of fauna, he explained.

Buffon never left Europe. He relied on natural history publications and the accounts of visitors. It was standard practice for such business travelers and missionaries to take notes on the animals they encountered, particularly previously unknown species. The count would compare the notes of travelers and distill them into a general description. This system had obvious faults, as Buffon himself admitted—there were tall tales in the mix. For example, one Peter Kalm, sent by the Swedish Academy to study the natural history of America, alleged to have seen a bear kill a cow by biting into its hide and then blowing into the puncture wound until the cow virtually exploded and expired. Compared with these fictions, less extreme accounts could be easy to accept, and Buffon used many less extreme briefings as prima facie evidence of degeneracy in Natural History.

Buffon’s Influence
Intellectual descendants of Buffon—such as the Prussian Abbé Cornelius de Pauw and the French Abbé Guillaume-Thomas Ray­nal—saw degeneration in the New World as all encompassing. The only flaw they found in Buffon was that he had not gone far enough. They extended the case to all Americans, including transplanted Europeans and their descendants. De Pauw, unrestricted by fact, claimed that American dogs were “perfectly mute.” As a confidant to Frederick the Great, who did not want Prussians leaving for opportunities in the New World, De Pauw most likely had personal motives for such propaganda. 

Raynal, a more respected and complex char­acter than de Pauw, wrote in his eight-volume A Phil­osophical and Political History of the Settlements and Trade of the Europeans in the East and West Indies, “One should not be surprised that America has yet to produce a good poet, a clever mathematician, a genius in even one art or science.” But Raynal had the capacity to revise his opinion, which he did after dining with Benjamin Franklin and several other Frenchmen and Americans in the late 1760s.

Franklin, of course, was a world-class scientist whose 1752 Royal Society publication about his lightning experiment was an instant classic. He devised an impromptu test of the effects of the New World. Jefferson told the story in a letter after hearing it from Franklin. “[Raynal] got on his favorite theory of the degeneracy of animals, and even of man, in America,” Jefferson wrote. Franklin noticed that the Americans were on one side of the table and the Frenchmen were on the other. “Let both parties rise,” Franklin said, “and we will see on which side nature has degenerated.” The Americans were bigger to a man, with the Abbé himself, in Jefferson’s own words, “a mere shrimp.” (One of the other Americans present said that any of them could have easily tossed one, or even two, of the Frenchmen out of the window.)

Raynal nonetheless published the slanderous first edition of A Philosophical and Political History. By the third edition, however, he had renounced his previous views. Unfortunately, the ideas were already well established in the European mind. 

Jefferson Counters the Count
The founding fathers were all too familiar with Buffon. It was one thing for Europeans, particularly the French, to refer to Americans as upstarts, malcontents and threats to monarchy—they were. It was another matter entirely to say that all life-forms in America, including its aboriginal population and its European immigrants, were degenerate.

Jefferson, the biggest Francophile of the found­ers, took it upon himself to refute Buffon and his supporters. Indeed, this effort became something of an obsession for the passionate naturalist, who once wrote to his daughter Martha, “There is not a sprig of grass that shoots uninteresting to me.”

Jefferson attacked Buffon with an over­whelming collection of facts. In his Notes on the State of Virginia, written when he was governor, Jefferson devoted the longest chapter to a point-by-point dismantling of the theory of degeneracy. He included tables of data, comparing measured sizes of animals, that disproved the count’s notions. He argued that the count’s ideas were conceptually unsound and that the data he was getting from travelers were inaccurate.

What proof existed, Jefferson asked, that the environments of the Old and New Worlds were so different? “As if both sides were not warmed by the same genial sun; as if a soil of the same chemical composition was less capable of elaboration into animal nutriment; as if the fruits and grains from that soil and sun ... gave less extension to the solids and fluids of the body, or produced sooner in the cartilages, membranes, and fibres, that rigidity which restrains all further extension, and terminates animal growth.” The truth, Jefferson wrote, “is that a Pygmy and a Patagonian, a Mouse and a Mammoth, derive their dimensions from the same nutritive juices.”

Jefferson was not the only founder to jump into the fray. John Adams called de Pauw’s ideas “despicable dreams.” In addition to his dinner demonstration, Franklin disputed the humidity argument. A world traveler and conscientious data collector, he pointed out in 1780 that the humidity, a supposed cause of degeneracy, was actually higher in Europe than in the colonies.

Alexander Hamilton, especially fearful of the degeneracy theory’s potential to stifle trade relations, defended America in the Federalist Papers: the only footnote in Federalist No. 11 is a rebuttal to de Pauw’s absurd assertion of nonbarking dogs.

And Jefferson’s eventual successor as president, James Madison, even served as a research assistant. He concludes a June 1786 letter to Jefferson with a discussion of weasels, complete with measurements: the American species was as large as its European equivalent. Madison wrote to his mentor that the finding “certainly contradicts [Buffon’s] assertion that of the animals common to the two continents, those of the new are in every instance smaller than those of the old.” In the midst of discussing such issues as a constitutional convention and the new country’s treasury requirements, both men clearly thought that battling Buffon was of national import.

The Answer of Alces alces
Jefferson believed that the methodical dismantling of degeneracy in Notes on the State of Virginia would go only so far in his quest to make people reject the unsupported ideas. He wanted to convince Buffon himself to publicly recant his theory. And so, before Jefferson set off for France to serve as ambassador, he was determined to present Buffon with an American animal so impressive as to impel the French luminary to change his opinion. Enter Alces alces: the moose.

Jefferson began his quest for a large moose by sending out a 16-question survey to his friends on the habits, size and natural history of the moose. And he made it clear that if hunters could procure for him the skeleton of a giant moose, he would be deeply indebted. Revolutionary War general and New Hampshire governor John Sullivan responded enthusiastically and was on the case when Jefferson left the U.S.

After arriving in France, Jefferson wrangled an invitation to meet Buffon. They had far-ranging conversations that included, of course, the theory of degeneracy. Minister Jefferson told the count that the European “reindeer could walk under the belly of our moose.” Jefferson left the meeting with the impression that the count would “give up the question” of degeneracy if he could but see a massive moose.

Finally, in the winter of 1786–1787, Jefferson received good news: Sullivan had procured the remains of a moose from a Captain Colburn, who had killed a seven-foot-high specimen in Vermont. It took 14 days for a team of men to deliver the moose to Sullivan’s home. Sullivan then hired a ship’s captain to take the moose with him on his next trip overseas.

All was going along according to plan, but the moose was inexplicably left on the dock when the ship set sail. Sullivan sent the bad news. Distraught, Jefferson believed his quest for the evidentiary moose had led to naught. He wrote to a friend that “the box, bones and all are lost; so that this chapter of natural history will still remain a blank.” What Jefferson did not yet know was that Sullivan had recouped the moose and hired another ship. The specimen arrived in Paris around October 1, 1787. 

Jefferson was ecstatic. He wanted to take the moose to Buffon personally, but the count was ill and not receiving visitors. So he sent the moose to Buffon’s assistant. Buffon apparently saw the moose, because Jefferson wrote that the giant creature had “convinced Mr. Buffon. He promised in his next volume to set these things right.” But six months later Buffon was dead, and no revisions to his theory were published. The influential Natural History would forever promote the theory of a degenerate New World.

Degeneracy’s Disappearance and Legacy
The idea of american degeneracy evolved with modification for at least another six decades before withering and leaving only a dried husk of general anti-Americanism. Two factions formed. Philosopher Immanuel Kant and poet John Keats accepted degeneracy wholesale. Keats described America as the single place where “great unerring Nature once seems wrong.” Kant, displaying a lack of pure reason, wrote of de Pauw that “even if nine-tenths of his material is unsupported or incorrect, the very effort of intelligence deserves praise and emulation, as making one think and not simply read thoughts.”

On the other side, Jefferson’s troops included writers Lord Byron, Washington Irving and Henry David Thoreau and geographer Jedidiah Morse (father of telegraph inventor Samuel). Byron called America “one great clime.” Irving skewered Buffon’s theory in The Sketchbook of Geoffrey Crayon, writing that he “will visit this land of wonders [Europe] ... and see the gigantic race from which I am degenerated.” Thoreau used his Walking as a platform “to set against Buffon’s account of this part of the world and its productions.” And Morse debunked degeneracy in the opening 10 pages of the geography textbook that the first generation of U.S. children would read in their schoolhouses.

These American writers, responding to the idea of New World inferiority, forged a counternarrative of America as a beautiful, vast, resource-rich region filled with robust individualists. The American identity to this day—and the rest of the world’s reactions to that modern self-image—can thus be partly traced back to the vigorous debunking, by Jefferson, his peers and his followers, of the accusation of American biological degeneracy.