Study Notes on the Mexican-American War
Introduction to the Mexican-American War
This section discusses the causes and effects of the Mexican-American War in the context of Unit 5 of the AP U.S. History curriculum.
Causes of the Mexican-American War
The Mexican-American War was primarily caused by several historical events and tensions:
Texas Independence (1836)
Texas declared its independence from Mexico.
Fought several battles against the Mexican government to achieve this independence.
Post-independence Tensions
After the conflict, tensions between Texas and the Mexican government temporarily cooled.
Despite independence, Texans desired to be annexed by the United States, a position not welcomed by the Mexican government.
Political Landscape
Presidents Jackson, Van Buren, Harrison, and Tyler all opposed the annexation of Texas.
This political stance shifted dramatically with the election of James K. Polk.
Polk assumed office in 1845 with a campaign promise to annex Texas.
Although Tyler initiated the annexation process, it was significantly influenced by Polk’s election.
The Diplomatic Breakdown
Polk faced a complex situation with Mexico regarding territorial claims:
Diplomat John Slidell's Mission (1845)
Slidell was sent to Mexico City to:
Propose the purchase of additional territories, specifically New Mexico and California.
Dispute the southern border with Mexico, the Mexican government claimed it was along the Nueces River, while the U.S. claimed it was the Rio Grande.
Failure of negotiations led to heightened tensions.
Prelude to War
In 1846, after escalating tensions, Polk sent troops to the Rio Grande area:
Deployment of General Zachary Taylor
Taylor's troops encountered Mexican forces, resulting in conflict.
During a skirmish, 11 American soldiers were killed.
Polk's Reaction
Outrage over the killings influenced his decision to go to war with Mexico.
On May 13, 1846, Congress declared war on Mexico, marking the official beginning of the Mexican-American War.
Outcomes of the Mexican-American War
The war resulted in significant territorial gains for the United States:
Military Success
American troops, although small in numbers, succeeded in claiming California and New Mexico territories.
Under General Winfield Scott's command, U.S. forces captured and occupied Mexico City, leading to negotiations.
Treaty of Guadalupe Hidalgo (1848)
Concluded the war with several important provisions:
Established the Rio Grande as the official border of Texas.
Included the Mexican Cession, wherein Mexico ceded California and New Mexico to the United States for $15 million.
Overall, the U.S. gained more than half of Mexico's territory, including land acquired from the Gadsden Purchase (1853).
Political and Social Implications
Wilmot Proviso (1846)
Proposed by Congressman David Wilmot, it aimed to prevent the expansion of slavery into territories acquired from Mexico.
The amendment was ultimately voted down but highlighted growing tensions surrounding slavery.
The Proviso is often cited as a precursor to the Civil War.
Impact on Residents of Acquired Territories
Mexican and Indian Population: Majority remained in the area post-annexation.
Civic Rights & Citizenship: The Treaty of Guadalupe Hidalgo promised U.S. citizenship to Mexicans but not to the Native Americans, who continued to face discrimination.
Indians would not gain citizenship rights until the 1930s.
Both groups experienced civil rights assaults, including voter discrimination and segregation in education.
Conclusion
Recap of the significant impacts of the war on both domestic politics and the social landscape, with implications for future events in U.S. history.
Final Note: Understanding these events is key to mastering Unit 5 of the AP U.S. History curriculum, preparing for examinations, and grasping the complexities of U.S.-Mexico relations and domestic policies.