Mexican-American War

Definition

The Mexican-American War was a conflict fought between the United States and Mexico from 1846 to 1848, primarily over territorial disputes and the U.S. desire to expand its territory westward. This war significantly altered borders in North America, resulting in the U.S. acquisition of present-day California, Arizona, New Mexico, Nevada, Utah, and parts of Colorado and Wyoming. The war exemplifies how territoriality and national boundaries can shift due to conflict, impacting both nations' political landscapes.

5 Must Know Facts For Your Next Test

1. The war began following disputes over the annexation of Texas and the border between Texas and Mexico, with both sides claiming different boundaries.
2. The U.S. military strategy involved capturing key Mexican cities, including Mexico City, which led to significant territorial gains for the United States.
3. Following the war, the Treaty of Guadalupe Hidalgo resulted in Mexico ceding approximately 525,000 square miles of territory to the U.S., changing the landscape of North America.
4. The Mexican-American War intensified debates over slavery in newly acquired territories, contributing to growing sectional tensions leading up to the Civil War.
5. This conflict was one of the first major instances where American expansionism was justified through ideology, namely Manifest Destiny.

Review Questions

• How did the outcomes of the Mexican-American War affect the borders and territorial claims in North America?
  • The outcomes of the Mexican-American War drastically altered North America's borders, as the United States acquired a significant amount of land from Mexico. The Treaty of Guadalupe Hidalgo resulted in the cession of territories including California, Arizona, New Mexico, Nevada, Utah, and parts of Colorado and Wyoming. This expansion not only changed physical borders but also set a precedent for future territorial claims by emphasizing military conquest as a means to achieve national interests.
• Discuss the relationship between Manifest Destiny and the motivations behind the Mexican-American War.
  • Manifest Destiny played a crucial role in motivating American involvement in the Mexican-American War by promoting a belief in America's divine right to expand its territory across North America. This ideology suggested that expansion was not only beneficial but inevitable, fueling public support for war against Mexico. As such, many Americans viewed this conflict as a fulfillment of their nation's destiny, which justified aggressive actions despite international tensions.
• Evaluate how the Mexican-American War contributed to sectional tensions within the United States in relation to slavery.
  • The Mexican-American War significantly intensified sectional tensions within the United States as debates arose regarding whether slavery would be permitted in new territories acquired from Mexico. The question of extending slavery into these regions led to heated arguments between Northern free states and Southern slave states, ultimately contributing to political divisions that culminated in the Civil War. The war's aftermath illustrated how territorial expansion could exacerbate existing conflicts related to slavery and governance.

Related terms

Treaty of Guadalupe Hidalgo: The treaty that ended the Mexican-American War in 1848, which resulted in Mexico ceding a large portion of its northern territory to the United States.

Manifest Destiny: The 19th-century doctrine that promoted the belief that the expansion of the U.S. across the American continents was both justified and inevitable.

Annexation of Texas: The process by which Texas joined the United States in 1845, an event that heightened tensions between the U.S. and Mexico and was a catalyst for the Mexican-American War.