On October 20, 1803, the Senate approved a treaty with France by which the United States purchased the Louisiana territory. As a result of this treaty, the nation doubled in size, adding territory that would become the states of Louisiana, Arkansas, Missouri, Iowa, Oklahoma, Kansas, Nebraska, North Dakota, South Dakota, and parts of Minnesota, New Mexico, Montana, Wyoming, and Colorado. The vote was 24 to 7.
In 1800 Spain had transferred the Louisiana Territory to France, whose Emperor Napoleon held ambitions for establishing a French colonial empire in North America. President Thomas Jefferson worried that French control of the Mississippi River might close off that vital transportation route to the American West. Jefferson instructed the American minister in Paris to try to purchase the city of New Orleans and the Florida Panhandle, for which Congress had appropriated $2 million. Jefferson advised the minister that he could bid as high as $10 million. But by then a slave revolt against the French in Haiti, and the strong possibility of war with Great Britain, had distracted Napoleon away from his vision of empire and made him needy for funds. To the American minister’s surprise, the French foreign minister asked how much the United States would pay for all of Louisiana. They settled on $15 million—an amount that translates into less than $300 million today—a bargain price.
Although eager to accept this vast territory, Thomas Jefferson also advocated a strict construction of the Constitution, and nowhere in the Constitution could he find authorization for the government to purchase new territory. Jefferson was a man of principle, but he recognized that expediency was sometimes the wisest policy. In the time it would take to enact and ratify a Constitutional Amendment, Napoleon might change his mind. Jefferson and his supporters in the Senate therefore devised an argument that the constitutional provision for governing a territory presupposed the right to acquire that territory. They had the votes to approve the treaty and appropriate the funds to pay for it. The Supreme Court later upheld their reasoning.
The seven senators who opposed the deal of the century—all of them Federalists—objected to Jefferson’s exercising executive authority in the absence of any specific constitutional authorization. Delaware senator Samuel White warned further that relocating settlers two or three thousand miles away from the capital might alienate their affections for the Union. Senator James Jackson, a Jeffersonian from Georgia, held a more positive opinion of the pioneers, and he predicted that within a century those settlers would turn a “wilderness” into a “seat of science and civilization.” He urged the senators to overcome their trepidations and approve the Louisiana purchase without delay, reminding them: “We have a bargain now in our power, which, once missed, we never shall have again.” Fortunately, two-thirds of the Senate agreed.