The Treaty of San Ildefonso (formally titled the Preliminary and Secret Treaty between the French Republic and His Catholic Majesty the King of Spain, Concerning the Aggrandizement of His Royal Highness the Infant Duke of Parma in Italy and the Retrocession of Louisiana) was a secretly negotiated treaty between France and Spain in which Spain returned the colonial territory of Louisiana to France. Official language(s) English and French Capital Baton Rouge Largest city New Orleans at last census; probably Baton Rouge since Hurricane Katrina Area  - Total  - Width  - Length  - % water  - Latitude  - Longitude Ranked 31st 134,382 km² 210 km 610 km 16 29°N to 33°N 89°W to 94°W Population...

The treaty was concluded on October 1, 1800 between Louis Alexandre Berthier representing France and Don Mariano Luis de Urquijo for Spain. The treaty was negotiated under some duress, as Spain was under pressure from Napoleon. The terms of the treaty did not specify the boundaries of the territory being returned, which later became a point of contention between Spain and the United States after France sold the Louisiana Purchase to the U.S. in 1803. October 1 is the 274th day of the year (275th in leap years) in the Gregorian Calendar. ... 1800 (MDCCC) was an common year starting on Wednesday (see link for calendar). ... Louis Alexandre Berthier, Marshal of France Louis Alexandre Berthier, prince de Neuchâtel (February 20, 1753 – June 1, 1815), marshal of France, Vice-Constable of France beginning in 1808, and chief of staff under Napoleon, was born at Versailles. ... For other uses, see Napoleon (disambiguation). ... From Frank Bond, Louisiana and the Louisiana Purchase. ... 1803 was a common year starting on Saturday (see link for calendar). ...

This treaty also affirmed the earlier Treaty of Alliance signed at San Ildefonso on August 19, 1796. That treaty is sometimes also referred to as the Treaty of San Ildefonso.

See also

• West Florida
• Adams-Onís Treaty

Map of East and West Florida in the early 1800s. ... The Adams-Onís Treaty of 1819 (formally titled the Treaty of Amity, Settlement, and Limits Between the United States of America and His Catholic Majesty, and also known as the Transcontinental Treaty of 1819, and sometimes the Florida Purchase Treaty) was a historic agreement between the United States and...

External link

• Treaty text from the Avalon Project