Answer:
1. The Third Treaty of San Ildefonso was a secret agreement signed on 1 October 1800 between the Spanish Empire and the French Republic by which Spain agreed in principle to exchange its North American colony of Louisiana for territories in Tuscany.
2. approximately 827,000 square miles
The Louisiana Purchase (1803) was a land deal between the United States and France, in which the U.S. acquired approximately 827,000 square miles of land west of the Mississippi River for $15 million.
