In the Louisiana Purchase the United States acquired more than 2,000,000 km² (800,000 square miles) of territory from France in 1803. It is one of the most important post independence events that dramatically altered the course of American and world history.

Far more than what we refer to today as the State of Louisiana, the lands purchased contained parts or all of present-day Arkansas, Missouri, Iowa, Minnesota west of the Mississippi River, North Dakota, South Dakota, Nebraska, Oklahoma, nearly all of Kansas, the portions of Montana, Wyoming, and Colorado east of the Rocky Mountains, and Louisiana on both sides of the Mississippi River including the city of New Orleans.

In 1802, Thomas Jefferson wanted to purchase New Orleans from Napoleon Bonaparte who had recently established himself as the undisputed ruler of France, and who had taken back the Louisiana area from Spain. Jefferson sent James Monroe to Paris to assist in the negotiations. The renewal of the war between the English and French was inevitable, and Napoleon had just faced a major military setback in the west when his army sent to conquer Santo Domingo was destroyed by a combination of yellow fever and fierce resistance led by Toussaint L'Ouverture. With his western forces diminished, Napoleon did not wish to utilize more of his army than absolutely necessary to defend Louisiana.

When the offer was made to purchase New Orleans, Napoleon realized that a strong United States ally was far better for France that a recapture of the colonies by England which he believed was an inevitable plan. (Napoleon was right, see the War of 1812.) Accordingly, Napoleon decided to sell the entire territory to the United States. The American negotiators were prepared to spend $2 million for New Orleans, but were dumbfounded when the entire region from the Gulf of Mexico to Canada and from the Mississippi River to The Rocky Mountians, which instantly doubled the size of the US, was offered for less than $20 million. The cost of the land was less than 3 cents per acre.

The Federalists strongly opposed the purchase, and favored close relations with England rather than France. The Federalists argued that the purchase was unconstitutional, and that the US had paid a large sum of money just to declare war on Spain. It was also feared that the political power of the Atlantic seaboard states would be threatened by the new citizens of the west, a clash of western farmers versus the merchants and bankers of New England. A group of Federalists led by Massachusetts senator Timothy Pickering went so far as to plan a separate northern confederacy and offered Vice-President Aaron Burr the presidency of the proposed break off if he would persuade New York to join. As a side note Alexander Hamilton helped stop the northern succession and showed hostility towards Burr, which grew in the 1801 election and ended with Hamilton's death in a duel with Burr in 1804.

See also: History of United States

File:Louisiana purchase treaty1.jpg

Public domain picture from U.S. National Archives and Records Administration