In December 1792, a 46-year-old French botanist named André Michaux arrived in Philadelphia to visit with some of the city’s most influential citizens.
Michaux had spent much of his adult life sloshing across muddy rivers and hacking through mosquito-infested forests. But he could clean up and turn on the charm when it suited his purposes, as it did when he paid a call on Benjamin Rush, the physician and signer of the Declaration of Independence, and Rush’s colleague Benjamin Barton, a well-known naturalist.
Both men belonged to the American Philosophical Society, the nation’s foremost scientific organization, which had been founded 50 years earlier to promote “useful knowledge.” Michaux, the educated son of a farmer, told Barton that it would be useful for the United States to have “geographical knowledge of the country west of the Mississippi.” His words were dry, but the idea was explosive: He wanted to transform the American continent, and with it his own reputation, by becoming the first explorer to forge a path to the Pacific.
Barton relayed Michaux’s idea to the society’s vice president, Thomas Jefferson, who also happened to be the U.S. secretary of state. Jefferson’s obsession with the frontier west of the Mississippi River was well known. His library at Monticello had more books about it than anywhere else on earth, filling his head with visions of woolly mammoths and purple volcanoes. More important, he viewed uniting the ends of the continent as destiny—a prerequisite for creating an American “Empire of Liberty.”But there was a difficulty. In 1792, America was bordered to the west by the Mississippi River and to the south by Florida. Much of the rest of what became the United States, including Louisiana, was controlled by Spain. And while Spain was a relatively docile neighbor, Jefferson feared that sending American explorers onto its soil might provoke a war. A French naturalist, on the other hand, was a perfect solution.
Jefferson had good reason to trust Michaux. France’s King Louis XVI had personally appointed Michaux to be his royal botanist, with a blank check to travel the world. He had survived being robbed by Bedouins in the Middle East and nearly froze with his native guides during an expedition in the Canadian wilderness. Upon moving to the United States and purchasing a large plantation in South Carolina, where he collected specimens before shipping them to France, he also became something of an expert on American Indians. His knack for getting into places unreachable by others led him to make hundreds of discoveries, a catalog of New World plant and animal life that would fill libraries.
On receiving Barton’s message, Jefferson wrote back to ask how soon Michaux could start. “In consequence of your note,” Barton replied on January 4, 1793, “I have waited on Mr. Michaux [and learned] he will engage in his scheme as soon as you think proper.”