<P> Following the establishment of the United States, the Americans controlled the area east of the Mississippi and north of New Orleans . The main issue for the Americans was free transit of the Mississippi to the sea . As the lands were being gradually settled by a few American migrants, many Americans, including Jefferson, assumed that the territory would be acquired "piece by piece ." The risk of another power taking it from a weakened Spain made a "profound reconsideration" of this policy necessary . New Orleans was already important for shipping agricultural goods to and from the areas of the United States west of the Appalachian Mountains . Pinckney's Treaty, signed with Spain on October 27, 1795, gave American merchants "right of deposit" in New Orleans, granting them use of the port to store goods for export . Americans used this right to transport products such as flour, tobacco, pork, bacon, lard, feathers, cider, butter, and cheese . The treaty also recognized American rights to navigate the entire Mississippi, which had become vital to the growing trade of the western territories . </P> <P> In 1798, Spain revoked the treaty allowing American use of New Orleans, greatly upsetting Americans . In 1801, Spanish Governor Don Juan Manuel de Salcedo took over from the Marquess of Casa Calvo, and restored the American right to deposit goods . However, in 1800 Spain had ceded the Louisiana territory back to France as part of Napoleon's secret Third Treaty of San Ildefonso . The territory nominally remained under Spanish control, until a transfer of power to France on November 30, 1803, just three weeks before the formal cession of the territory to the United States on December 20, 1803 . A further ceremony was held in St. Louis, Upper Louisiana regarding the New Orleans formalities . The March 9--10, 1804 event is remembered as Three Flags Day . </P> <P> James Monroe and Robert R. Livingston had traveled to Paris to negotiate the purchase of New Orleans in January 1803 . Their instructions were to negotiate or purchase control of New Orleans and its environs; they did not anticipate the much larger acquisition which would follow . </P> <P> The Louisiana Purchase was by far the largest territorial gain in U.S. history . Stretching from the Mississippi River to the Rocky Mountains, the purchase doubled the size of the United States . Before 1803, Louisiana had been under Spanish control for forty years . Although Spain aided the rebels in the American Revolutionary War, the Spanish didn't want the Americans to settle in their territory . </P>

Who negotiated the price of the louisiana purchase