3 minute read

Louisiana Purchase

The Louisiana Purchase of 1803 doubled the size of the United States, gave the country complete control of the port of New Orleans, and provided territory for westward expansion. The 828,000 square miles purchased from France formed completely or in part thirteen states: Arkansas, Colorado, Iowa, Kansas, Louisiana, Minnesota, Missouri, Montana, Nebraska, North Dakota, Oklahoma, South Dakota, and Wyoming. President THOMAS JEFFERSON was unsure if the Constitution authorized the acquisition of land, but he found a way to justify the purchase.

France originally claimed the Louisiana Territory in the seventeenth century. In 1763 it ceded to Spain the province of Louisiana, which was about where the state of Louisiana is today. By the 1790s U.S. farmers who lived west of the Appalachian Mountains were shipping their surplus produce by boat down rivers that flowed into the Gulf of Mexico. In 1795 the United States negotiated a treaty with Spain that permitted U.S. merchants the right of deposit at New Orleans. This right allowed the merchants to store their goods in New Orleans without paying duty before they were exported.

In 1800 France, under the leadership of Napoléon, negotiated a secret treaty with Spain that ceded the province of Louisiana back to France. President Jefferson became concerned that France had control of the strategic port of New Orleans, and sought to purchase the port and West Florida. When France revoked the right of deposit for U.S. merchants in 1802, Jefferson sent JAMES MONROE to Paris to help ROBERT R. LIVINGSTON convince the French government to complete the sale. These statesmen warned that the United States would ally itself with England against France if a plan were not devised that settled this issue.

Monroe and Livingston were authorized by Congress to offer up to $2 million to purchase the east bank of the Mississippi; Jefferson secretly advised them to offer over $9 million for Florida and New Orleans.

Napoléon initially resisted U.S. offers, but changed his mind in 1803. He knew that war with England was imminent, and realized that if France were tied down with a European war, the United States might annex the Louisiana Territory. He also took seriously the threat of a U.S.-English alliance. Therefore, in April 1803 he instructed his foreign minister, Charles-Maurice de Talleyrand-Périgord, to negotiate with Monroe and Livingston for the United States' purchase of the entire Louisiana Territory. Acting on their own, the U.S. negotiators agreed to the price of $15 million, with $12 million paid to France and $3 million paid to U.S. citizens who had outstanding claims against France. The purchase agreement, dated April 30, was signed May 2 and reached Washington, D.C., in July.

President Jefferson endorsed the purchase but believed that the Constitution did not provide the national government with the authority to make land acquisitions. He pondered whether a constitutional amendment might be needed to legalize the purchase. After consultations Jefferson concluded that the president's authority to make treaties could be used to justify the agreement. Therefore, the Louisiana Purchase was designated a treaty and submitted to the Senate for ratification. The Senate ratified the treaty October 20, 1803, and the United States took possession of the territory December 20, 1803.

The U.S. government borrowed money from English and Dutch banks to pay for the acquisition. Interest payments for the fifteen-year loans brought the total price to over $27 million. The vast expanse of land, running from the Mississippi River to the Rocky Mountains and from

Map showing area of Louisiana Purchase and surrounding areas.

the Gulf of Mexico to the Canadian border, is the largest ever added to the United States at one time. The settling of the territory played a large part in the debate over SLAVERY preceding the Civil War, as Congress grappled with the question of whether to allow slavery in new states, such as Missouri and Kansas.


Levasseur, Alain A., and Roger K. Ward. 1998. "300 Years and Counting: the French Influence on the Louisiana Legal System." Louisiana Bar Journal 46 (December): 300.

Ward, Roger K. 2003. "The Louisiana Purchase." Louisiana Bar Journal 50 (February): 330.

Additional topics

Law Library - American Law and Legal InformationFree Legal Encyclopedia: Load Lines to Market value