Monroe is most famous for the foreign policy doctrine that bears his name. Devised by John Quincy Adams, the 1823Monroe Doctrine warned European powers to stay out of the New World and stated that the region was closed to further colonization. In return, the United States would not interfere with Europe’s affairs and would recognize all existing European colonies in the New World. The doctrine also pledged Monroe’s support for the growth of democracy throughout the western hemisphere.
The Monroe Doctrine, undoubtedly Monroe’s greatest contribution as president, has become one of the defining features of American foreign policy. Ironically, it was the British who first proposed the doctrine to John Quincy Adams, for they wanted to protect their West Indian colonies from other European powers—and, secretly, to curb U.S. expansion in the Caribbean. Sensing Britain’s motives, Adams encouraged Monroe to issue the doctrine on his own, which would give the United States more freedom than a joint U.S.-British declaration would. Ultimately, however, the British supported the Monroe Doctrine as issued, and much of the Doctrine’s authority came from the Royal Navy’s vigorous enforcement of it.