Which policy asserted that the Western Hemisphere should be free from European colonization and remain under U.S. influence?

• A. The Truman Doctrine.
• B. The Open Door Policy.
• C. The Monroe Doctrine.
• D. The Roosevelt Corollary.

Answer: (C)

The main idea being tested is the right to hemispheric influence and exclusion of European colonization. In the Monroe Doctrine, proclaimed in the early 1800s, the United States declared that the Western Hemisphere was no longer open to new European colonization and that European powers should keep out of the Americas. It also established that the United States would be the dominant influence in the region, signaling that imperial ambitions from Europe in this area would be met with American opposition. This set a clear expectation that Latin American nations would be supported by the United States and that European interference would be resisted.

Context helps: this era followed many independence movements in the Americas, and the United States wanted to prevent recolonization or entanglement in European affairs. The policy framed the hemisphere as within America’s sphere of influence, while also asserting a cautionary stance toward European powers. Later, the Roosevelt Corollary would expand on this by justifying U.S. intervention in Latin American countries to maintain stability, but the core claim of keeping European colonization out and establishing U.S. leadership in the region comes from the Monroe Doctrine.

Choices that focus on other regions or issues don’t match this aim: policies concerning China, global Cold War containment, or direct intervention to enforce stability in the Americas reflect different objectives and time periods.