Heimler’s History: Mexican-American War

Introduction

Texas Independence (1836):
- Texas declared independence from Mexico.
- Tensions cooled post-independence, but issues remained.
Annexation of Texas:
- Texans didn't want to remain independent; they wanted U.S. annexation.
- Presidents Jackson, Van Buren, Harrison, and Tyler avoided annexation.
- James K. Polk's election changed the stance; his campaign promised Texas annexation.
- John Tyler began the annexation process, influenced by Polk’s election.
- Mexico was unhappy about annexation.
Diplomatic Efforts:
- Polk sent John Slidell to Mexico City:
  - Proposed purchase of New Mexico and California territories - rejected by Mexico.
  - Dispute over southern border: U.S. claimed Rio Grande, Mexico claimed Nueces River.
Military Actions:
- Polk sent General Zachary Taylor to the Rio Grande, triggering conflict.
- Mexican troops engaged, resulting in 11 American deaths.
- Polk used this to justify a war, which Congress declared on May 13, 1846.

Territorial Gains:
- Treaty of Guadalupe Hidalgo (1848):
  - Established Rio Grande as the border.
  - Mexican Cession: Mexico ceded California and New Mexico for $15 million.
  - Gadsden Purchase added more territory in 1853.
- Mexico lost over half its territory to the U.S.
Wilmot Proviso:
- Proposed amendment to prohibit slavery in new territories.
- Highlighted tensions over slavery.
- Although defeated, it underscored economic vs. moral reasons for free soil.
- Seen as an early factor leading to the Civil War.
Impact on Inhabitants:
- Non-American residents (Mexicans and Indians) largely stayed.
- Treaty of Guadalupe Hidalgo promised U.S. citizenship to Mexicans.
- Indians were excluded from citizenship, facing discrimination.
- Civil rights assaults including voter and educational discrimination.