The Monroe Doctrine of 1823 was regarded as a very smart move that forbade further European colonization of the Americas, but preceding it was the "Transcontinental Treaty."

This treaty was considered by many to be Adams's and the country's greatest diplomatic victory. It was signed with Spain on February 22, 1819, and ratified February 22, 1821. It was pioneering because of the far-reaching territory the U.S. acquired through it. What territory did this include?