What was the Louisiana Purchase?

The Louisiana Purchase was the acquisition by the United States of America of 828,800 square miles (2,147,000 km2) of the French territory Louisiane in 1803. This was the entire valley of the Mississippi as claimed by the French, an area as large as the existing United States at the time.

The purchase was one of the greatest real estate deals that has ever existed in the United States (along with the purchase of Alaska in 1867). President Thomas Jefferson offered 10 million dollars for the port of New Orleans so that the US could have access to the Mississippi River. Instead he received the entire area known as the Louisiana Territory and the New Orleans port and only paid 15 million dollars for it. Which means he paid about 3 cents per acre to buy the entire Mississippi River valley from Napoleon Bonaparte.
America wanted to buy New Orleans from France because the Mississippi was there only way of getting crops from the West to the market by shipping it out from the port in New Orleans. Louisiana was given to Spain after France lost the French and Indian War, but under Napoleon Bonaparte, Louisiana was given back to France. Napoleon was going to have people settle in the territory and farm crops for the slaves who worked in the sugar plantations in the West Indies. The president at the time, Jefferson, sent James Monroe to France to offer to buy New Orleans for $7 million. However, France had just lost its sugar plantations in what is modern day Haiti and had no more use for Louisiana. In addition, Britain and France were on the brink of war and France knew they could not hold on to Louisiana much longer, so they decided to sell all of Louisiana to the US for $15 million. Monroe accepted the deal and the Senate ratified the Louisiana Purchase Treaty later that year. This was the first step in Manifest Destiny as the US spread across the North American continent, and by buying Louisiana they had more than doubled the original size of the US.