John Quincy Adams is considered to be one of the prime supporters of the concept of manifest destiny. As Secretary of State under James Monroe, Adams crafted a document known as the Monroe Doctrine. It basically warned all foreign powers that any colonization of territory in the Americas would be considered as aggression against the United States.

It was a watershed moment in U.S. foreign policy. The United States was claiming the right to intervene anywhere in the Americas if foreign powers were involved. Later, Teddy Roosevelt would expand the policy to allow the U.S. to intervene in the case of “flagrant and chronic wrongdoing by a Latin American Nation.” That gave the U.S. the right to address internal issues in other nations as well as external influences.

These policies put the United States in the role of policing the Americas. They would lead to numerous military interventions as well as countless covert operations. Though John Quincy Adams didn’t achieve his expansionists goals in Latin America, his dream of regional domination lived on long after him.