As the strength of the United States continued to grow after 1815, the power of Spain continued to decline. Following the example set by the United States, Spanish colonies in Central and South America overthrew their Spanish governors and became independent republics.
President Monroe was worried. Spain had asked some of its European allies to help it regain its lost territories. Other European countries seemed to be planning to take over former Spanish colonies. Monroe was afraid that if the European powers sent armies into Central and South America, the independence of the United States might also be in danger. He decided to act.
In 1823 President Monroe sent a message to Congress. In it, he outlined what has become known as the Monroe Doctrine. It contained the following points:
The principles of the Monroe Doctrine became the basis of American foreign policy for almost a hundred years. Even today, the Monroe Doctrine continues to guide the foreign policy decisions of our Presidents.