Third Treaty of San Ildefonso

treaty between France and Spain involving the colonial territory of Louisiana

The Third Treaty of San Ildefonso (short for 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 treaty between France and Spain. In it, Spain gave the territory of Louisiana to France.