LOUISIANA PURCHASE, a large portion of the area of the west central section of the United States of America, pur chased from the French Republic in 1803. The "Louisiana," to which France held explorer's title, originally included the entire valley of the Mississippi (see LOUISIANA) but that part of the territory which was ceded by her to Spain in 1763 (England re fusing it, preferring the Floridas), retroceded to France in 1800, and ceded by Napoleon to the United States—in violation of his pledge to Spain that he would not alienate the province—em braced only the portion west of the river and the island of New Orleans on the east (and, as might be claimed with some show of argument, West Florida to the Perdido river).
With the rapid increase of American settlement in the trans Allegheny region, the freedom of the Mississippi had become of vital importance to the western people, and Spain had recog nized these interests in her treaty with the United States of 1794, by guaranteeing freedom of navigation and the privilege of deposit at New Orleans. The transfer of Louisiana from a weak neighbour to so powerful and ambitious a State as France was naturally unwelcome to the United States, and Robert R. Livingston, the American minister in Paris, was instructed by Secretary of State Madison to endeavour to prevent the consummation of the retro cession; or, should that be irrevocable, to endeavour to buy the Floridas (either from France, if they had passed with Louisiana, or through her goodwill from Spain)—or at least West Florida— and if possible New Orleans, so as to give the United States a secure position on the Mississippi, and ensure her commerce.
In his preliminary propositions Livingston lightly suggested to Talleyrand a cession of Louisiana to satisfy certain claims of American merchants for spoliations by French cruisers ; follow ing it with the more serious demand that France should pledge observance of the Spanish concession to the Mississippi trade. This pledge Napoleon readily gave. But during these negotia tions a suspension by the Spanish governor of the right of deposit aroused extreme apprehension in America and resulted in warlike votes in Congress. Of these, and of London reports of a British expedition against New Orleans preparing in anticipation of the imminent rupture of the peace of Amiens, Livingston made most capable use; and pressed for a cession of West Florida, New Orleans and Louisiana north of the Arkansas river. But without New Orleans Louisiana was of little present worth, and Napoleon —the collapse of whose American colonial schemes seemed in volved in his failure in Santo Domingo, and who was persuaded he could not hold Louisiana against Great Britain—suddenly offered to Livingston the whole of the province. Livingston dis
claimed wanting the part below the Arkansas. In even mentioning Louisiana he had gone outside his instructions.
At this stage James Monroe became associated with him in the negotiations. They were quickly closed, Barbe-Marbois acting for Napoleon. By three conventions signed on April 3o, 1803, the American ministers, without instructions, boldly accepted for their country a territory approximately 1,000,000 sq.m. in area—about five times the area of continental France. For this imperial do main, perhaps the richest agricultural region of the world, the United States paid 6o,000,000 francs ($11,250,000) outright, and assumed the claims of her citizens against France to the extent of 20,000,000 francs ($3,750,000) additional; the interest pay ments incidental to the final settlement raising the total eventually to $27,267,622, or about four cents an acre.
The exact limits of the acquisition were not definitely drawn. The French archives show that Napoleon regarded the Rio Grande as the western boundary of the territory of which he was to take possession, and the United States up to 1819 ably maintained the same claim. She also claimed all West Florida as part of Louisiana—which, in the usage of the second half of the 18th century, it apparently was not. When she acquired the Floridas in 1819-21, the claim to Texas was abandoned. The line then adopted between the American and Spanish possessions on the west followed the Sabine river from the Gulf of Mexico to the parallel of 32° N., ran thence due north to the Red river, followed this to the meridian of ioo° W. and this line north to the Arkansas river, thence along this to its source, thence north to the parallel of 42°, and along this line to the Pacific. Such is the accepted description of the western boundary of the Louisiana Purchase— waiving Texas—thus retrospectively determined, except that the original boundary ran with the crest of the Rocky mountains north of its intersection with the parallel of 42°. No portion of the purchase lay west of the mountains, although for some years after 1870 the official maps of the U.S. Government included Oregon as so acquired—an error finally abandoned by 1900.