 In addition to its desire to expand west of the mountains, the United States wanted to acquire Florida.It wanted to gain free commerce on western rivers, and to prevent Florida from being used a base for possible invasion of the U.S. by a European country.In order to obtain a port on the Gulf of Mexico with secure access for Americans, United States diplomats in Europe were instructed to try to purchase the Isle of Orleans and West Florida from whichever country owned them.