The U.S.-Mexico War: A Response to Sectional Tensions Over Slavery

Early History of Texas and Mexican Independence

• 1830s: Texas was part of Mexico's Northern Frontier, including areas now known as Texas, Arizona, Utah, Nevada, New Mexico, and California.
• 1821: Mexico declared independence from Spain.
  • Texas had a small population (~2,000 Mexicans)
• 1830s: Moses Austin and his son Stephen Austin encouraged American settlement in Texas.
  • 7,000 Americans moved in.
  • Mexico allowed settlers while banning more immigration later.

Slavery and Autonomy Issues

• Mexico abolished slavery, but American settlers (Anglos) in Texas used workarounds to keep slaves.
• Austin and his elites called for more autonomy and legally protected slavery.
• 1835: Santa Ana led an expedition to remove American settlers.
• 1836: American citizens in Texas reached 35,000; organized an army and declared independence within Mexico.
  • Battle of the Alamo (March 13, 1836)
  • Battle of San Jacinto (April 21, 1836)
  • Texas gained independence; Mexico didn't recognize it.

Texas Annexation and U.S. Politics

• Texas sought to join the U.S., but faced controversy due to slavery and border disputes.
• Presidents Andrew Jackson and Martin Van Buren ignored annexation requests.
• Texas remained independent due to U.S. reluctance to accept a large slave state.

U.S. Political Landscape in 1830s-40s

• 1836: Martin Van Buren succeeded Andrew Jackson.
• 1840: William Henry Harrison (Whig) won the presidency but died shortly after; succeeded by John Tyler.
  • Discussions about his possible cause of death.

Election of 1844 and President James K. Polk

• Van Buren (Democrat) opposed Texas annexation leading to war; Southern Democrats nominated James K. Polk
  • Polk's slogan: 54°40' or Fight (northwest boundary disputes with Britain)
  • The Oregon Territory issue: settled at the 49th parallel.
  • Polk won; Congress annexed Texas in 1845 via joint resolution.

Lead-Up to the U.S.-Mexico War

• Polk sent John Slidell to negotiate Texas border and buy California: failed.
• 1846: Polk sent troops to disputed regions, deliberately provoking war.
  • Skirmishes were used as justification for war.
  • Congress declared war on Mexico (May 13, 1846)

Opposition to the War

• Abraham Lincoln and others opposed the war, questioning the motives and actions.

Key Battles and Events

• General Zachary Taylor's advances and battles in northern Mexico.
• The San Patricios joined the Mexican side.
• The stalemate at Buena Vista (Feb 1847).
• General Winfield Scott's advance on Mexico City:
  • Veracruz siege (March 1847)
  • Churubusco battle and capture of San Patricios
• Mexico City fell (Sept 1847).

Treaty of Guadalupe Hidalgo (Feb 1848)

• Mexico ceded large territories, including California and New Mexico.
• The Rio Grande established as Texas' border.
• Mexicans in ceded lands given U.S. citizenship but faced discrimination.

Consequences and Aftermath

• Rapid decline in native population in California.
• The All Mexico Movement: failed plans for further expansion.
• Northern and Southern tensions within the U.S. exacerbated by the war.
  • Northern Whigs opposed southern expansion.
  • John C. Calhoun expressed racist views about including Latin Americans in the U.S.

Key Takeaways

• The U.S.-Mexico War heightened sectional tensions within the U.S.
• The acquisition of new territories intensified debates over slavery.
• The expansionist agenda faced opposition and had significant political and social consequences.