The Louisiana Purchase, Fifteen Million Dollars and Half a Continent

In early March of eighteen oh four, the formal transfer of Upper Louisiana territory took place in Saint Louis, and the ground beneath this state changed sovereigns for the last time. France had sold the entire Louisiana territory to the United States for fifteen million dollars, less than three cents an acre for eight hundred twenty-eight thousand square miles, a transaction so enormous that President Thomas Jefferson himself doubted whether the Constitution actually authorized it. Napoleon Bonaparte made the offer because he needed cash for European wars and had lost faith in his North American ambitions after the Haitian Revolution destroyed his army in the Caribbean.

Jefferson needed control of New Orleans to guarantee American commerce down the Mississippi River. Neither man fully anticipated what the deal would mean: the effective doubling of the young republic's size, and the opening of a continental interior that would take a century to fully incorporate. Lewis and Clark departed from Camp Dubois, on the Illinois side of the Mississippi near the mouth of the Missouri, in May of eighteen oh four.

Their mission was to survey what Jefferson had bought, find a navigable route to the Pacific, and report on the peoples, plants, animals, and geography of the interior. They returned in September of eighteen oh six having done all of that, and their journals became the foundational text of American westward imagination. What the Purchase meant for the Indigenous peoples already living across this vast territory was a different matter entirely.

The United States now claimed sovereignty over lands where the Osage, the Sioux, the Mandan, and dozens of other nations had long held their own. The transaction was conducted without their knowledge or consent, a legal fiction of European-to-American title transfer that would be enforced over the following century by treaty, displacement, and war. The land was bought.

What came with it was considerably more complicated.