MEGA Elementary Education Multi-Content Practice Test

Which factor most contributed to the tensions leading to the Mexican War of 1846-1848?

1. Mexican raids on U.S. settlements in New Mexico

2. The U.S. annexation of Texas

3. Mexican aid to U.S. abolitionists in the South

4. The U.S. seizure of California

The correct answer is: The U.S. annexation of Texas

The U.S. annexation of Texas is recognized as the primary factor contributing to the tensions that led to the Mexican War of 1846-1848. When Texas declared independence from Mexico in 1836 and subsequently sought to join the United States, it sparked significant conflict over territorial claims and the principle of Manifest Destiny, which was a widely held belief that Americans were destined to expand across the continent. The annexation was controversial and escalated tensions not only because it represented a significant territorial gain for the United States but also because Mexico still viewed Texas as a breakaway state. The U.S. decision to officially annex Texas in 1845 was seen by Mexico as an act of aggression and a violation of its sovereignty. This act directly contributed to the strain in U.S.-Mexican relations and was a significant catalyst for the war. While other factors, such as tensions from Mexican raids or the seizure of California, played roles in the conflict, they were largely influenced by the underlying issues stemming from the annexation of Texas. Therefore, the annexation is best understood as the most critical factor in the buildup to the Mexican War.