1800:Spain cedes this large territory to France
Under 
intense pressure, Spain ceded the Louisiana territory back to France in a secret 
treaty arranged in October 1800  only a day after the French had concluded a... [DOC] [TLE] Treaty of San Ildefonso 1800 - The Napoleon Series [PAR] October 1, 1800 ... and the Treaty of Madrid, 21 March 1801, Spain returned to 
France the territory of Louisiana which France had ceded to Spain in 1763.