Louisiana Purchase

The Louisiana Purchase was the 1803 acquisition by the United States of roughly 828,000 square miles of French territory in North America, agreed under a treaty signed in Paris on 30 April 1803 by American negotiators Robert Livingston and James Monroe and the French government of Napoleon Bonaparte, who had regained the territory from Spain only three years earlier. The United States paid 15 million dollars, a price of roughly eighteen dollars per square mile, for the whole of the Mississippi River's western drainage basin, stretching from the Gulf of Mexico toward the Rocky Mountains and encompassing all or part of fifteen future American states along with parts of two Canadian provinces. President Thomas Jefferson, though he had constitutional doubts about the federal government's power to acquire new territory by treaty, pursued the purchase chiefly to secure American control of the port of New Orleans and free navigation of the Mississippi River for western farmers, and the deal nearly doubled the nominal territory of the United States overnight. Because the purchase conveyed only France's own claim to the land, and most of the territory remained inhabited and controlled by Native American nations, its practical effect was primarily to transfer to the United States the preemptive right to acquire Indigenous land there by treaty or by conquest, a process of dispossession that continued for decades after 1803 and, by some modern estimates, cost the government many times the original purchase price in subsequent payments and wars.