Louisiana Purchase Summary

  • Last updated on November 10, 2022

The largest single acquisition of territory by the United States, the Louisiana Purchase more than doubled the size of the nation, creating a vast new territory to be explored and incalculable commercial opportunities to be exploited. The purchased territory accounts for 23 percent of the territory of the modern United States.

Before the era of the railroads, water transportation was by far the most efficient way to move large, bulky cargoes. American commerce tended to move in a counterclockwise direction because of the Ohio and Mississippi Rivers and their tributaries. Farm commodities, lumber, and other bulk goods from the trans-Appalachian west moved down the river systems, eventually reaching the Mississippi and the port of New Orleans. From New Orleans, these goods would be taken by sea to the eastern coast or exported to Europe. Because of the importance of this river traffic, it was imperative that the United States maintain access to the port of New Orleans.Louisiana Territory

While New Orleans and what was considered the “Louisiana Territory” was under Spanish control, the United States negotiated the Pinckney Treaty with Spain in 1795. Under this agreement, American shippers were granted the “right of deposit” in New Orleans–the right to ship goods in and out of New Orleans and to store goods there while awaiting shipment.

When Napoleon I of France came to control Spain as part of his European empire, he forced the Spanish government to give control of Louisiana back to the French in 1800; this cession was formalized in the Treaty of Madrid in March, 1801. Even though France technically controlled the Louisiana territory after that date, Spanish colonial officials remained in place in America until the region was turned over to U.S. control. In October, 1802, the Spanish colonial administrators in Louisiana revoked the right of deposit for American shippers.

The Offer

When President Thomas Jefferson learned of the revocation of the right of deposit, he sent James Monroe, JamesMonroe to Paris to assist Robert Livingston, RobertLivingston, the U.S. ambassador to France, in making an offer to the French for the purchase of New Orleans. They were authorized to offer $2 million for New Orleans, or up to $10 million for New Orleans and what was then called “West Florida”–the coastal region of present-day Alabama and Mississippi.

Monroe arrived in Paris in April, 1803, and was astonished to learn that Napoleon’s prime minister, Charles Talleyrand, had already offered to sell the United States all of the Louisiana region for $15 million. Livingston and Monroe had no authorization to proceed with such negotiations, but they immediately wrote to Jefferson and Secretary of State James Madison for instructions, indicating that they were proceeding on the assumption that the forthcoming instructions would be to make the purchase. Monroe and Livingston signed a draft treaty on April 30, 1803, and the U.S. Senate ratified the purchase treaty on October 20, 1803. On December 20 of that year, the U.S. took formal possession of the region in a ceremony at New Orleans.

The Purchase

The purchase price of $15 million was agreed on, but the United States did not pay that much directly to France. Citizens of the United States had claims for damages against France amounting to $3.75 million, and the United States agreed to pay those claims, and remitted to France the balance of $11.25 million. To make the purchase, the U.S. borrowed money from the London firm of Baring Bank and from Hope and Company of Amsterdam.

In the short run, the major significance of the Louisiana Purchase was that the right of American commerce to navigate the Mississippi was permanently secured. Even before much settlement advanced into the lands the United States had acquired, the economic development of the area between the Appalachian Mountains and the Mississippi caused the traffic flowing through New Orleans to boom. In the long run, the settlement and economic development of the vast territory gained in this acquisition had an even more pervasive impact on American economic history. The purchase increased the size of the United States by approximately 140 percent. Eventually, all or part of more than a dozen states would be created out of this territory.

Further Reading
  • DeConde, A. This Affair of Louisiana. New York: Charles Scribner’s Sons, 1976. Long considered the standard work on the Louisiana Purchase.
  • Joy, Mark S. American Expansionism, 1783-1860: A Manifest Destiny? London: Pearson Education, 2003. Brief introduction to the subject of America’s expansion; includes many learning aids, such as a time line, glossary, who’s who, and bibliography.
  • Kuka, Jon. A Wilderness So Immense: The Louisiana Purchase and the Destiny of America. New York: Alfred A. Knopf, 2003. Major work on the Louisiana Purchase; detailed and well-written.
  • Owsley, Frank L., and Gene A. Smith. Filibusterers and Expansionists: Jeffersonian Manifest Destiny, 1800-1821. Tuscaloosa: University of Alabama Press, 1997. Valuable work that puts the purchase of Louisiana into the overall context of the foreign policy of Presidents Jefferson, Madison, and Monroe.
  • Perkins, B. The Creation of a Republican Empire, 1776-1865. Vol. 1 in The Cambridge History of American Foreign Relations. New York: Cambridge University Press, 1993. A standard history of American diplomacy that covers the Louisiana Purchase in detail.
  • Weeks, William Earl. Building the Continental Empire: American Expansionism from the Revolution to the Civil War. Chicago: Ivan R. Dee, 1996. Brief, accessible treatment of American continental expansion, with suggestions for further reading.


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Categories: History