The purchase by the United States from France of the huge Louisiana Territory (roughly 828,000 square miles) in 1803. President Thomas Jefferson ordered the purchase negotiations. He, and others, feared that the French, under the warring leadership of Napoleon, wanted to establish a new French empire in North America. Neither Napoleon or the French had such ambitions, but Napoleon was quite happy to exchange the vast landholdings of the French for the cash that was being offered – about $15,000,000. The area that they sold, extending from the Mississippi River to the Rocky Mountains, more than doubled the geographical size of the United States.