Definition of Monroe, James
- (1758–1831), 5th president of the US 1817–25. In 1803, while minister to France under President Jefferson, he negotiated and ratified the Louisiana Purchase. During his presidency, the Adams-Onis Treaty 1819, which allowed the US to acquire Florida from Spain, was negotiated. A Democratic-Republican, he is chiefly remembered as the originator of the Monroe Doctrine.