Final answer:
The Monroe Doctrine maintained that European powers should not pursue any future colonization in the Americas. The doctrine was outlined by President James Monroe in his annual message to Congress in 1823 and aimed to protect the independence of nations.
Step-by-step explanation:
The Monroe Doctrine maintained that European powers should not pursue any future colonization in the Americas. The doctrine was outlined by President James Monroe in his annual message to Congress in 1823, with the help of his Secretary of State, John Quincy Adams. Its purpose was to assert the United States' stance on European interference in the Americas and to protect the independence of nations in the Western Hemisphere.