Causes of the War
- The war began as part of the United States’ belief in Manifest Destiny, the idea that it was America’s divine mission to expand its territory across North America.
- The annexation of Texas (1845), which Mexico still considered its territory after Texas declared independence in 1836, sparked major tensions between the two nations.
- Disagreement over the Texas–Mexico border further escalated conflict: the U.S. claimed the Rio Grande as the boundary, while Mexico insisted it was the Nueces River.
- Economic and political motivations also played a role: many Americans wanted access to Mexican lands, ports on the Pacific (especially California), and trade routes that would open Asia to U.S. commerce.
- The war began in April 1846, when fighting broke out between U.S. and Mexican troops near the Rio Grande, an area claimed by both countries.
Key Events and Outcomes of the War
- The United States invaded Mexico on two fronts: General Zachary Taylor advanced from the north, while General Winfield Scott landed at Veracruz and captured Mexico City (1847).
- The war ended with the Treaty of Guadalupe Hidalgo (1848), which forced Mexico to cede nearly half of its territory, including present-day California, Nevada, Utah, Arizona, and parts of Colorado and New Mexico, to the United States.
- In exchange, the U.S. paid Mexico $15 million and assumed $3.25 million in claims by U.S. citizens against Mexico.
The Treaty of Guadalupe Hidalgo (1848)
Background
- The Treaty of Guadalupe Hidalgo, signed on February 2, 1848, ended the Mexican–American War (1846–1848), a conflict sparked by U.S. expansionist ambitions under Manifest Destiny and the disputed annexation of Texas (1845).
- The war resulted in a decisive U.S. victory and massive territorial losses for Mexico, permanently reshaping North America’s political map.
Terms of the Treaty
- Mexico ceded over 500,000 square miles (about half its territory) to the United States, including present-day California, Nevada, Utah, Arizona, New Mexico, and parts of Colorado and Wyoming.
- The Rio Grande was recognized as the southern border of Texas.
- The United States agreed to pay $15 million in compensation and assume approximately $3 million in Mexican debts owed to American citizens.
- The treaty promised to protect the property, language, and civil rights of Mexicans living in the newly annexed territories.
Causes and Motivations
- Rooted in the ideology of Manifest Destiny, Americans believed they were destined to expand westward across the continent.
- Tensions over the Texas–Mexico border and President James K. Polk’s expansionist policies provoked open war.
- Mexico, politically unstable and militarily weaker, was unable to resist U.S. invasion effectively.
Consequences and Impact
For the United States
- The treaty fulfilled Manifest Destiny, vastly increasing U.S. size and resources.
- It intensified the sectional conflict over whether new territories would allow slavery, contributing to the causes of the American Civil War (1861–1865).
- The victory boosted national pride and the image of U.S. military power.
For Mexico
- Mexico suffered a crushing territorial and psychological loss, fueling long-term resentment toward the United States.
- The loss deepened internal divisions and political instability, weakening Mexico’s government for decades.
- Many Mexicans in annexed regions became second-class citizens, losing land and legal rights despite treaty guarantees.
Legacy
- The Treaty of Guadalupe Hidalgo marked a turning point in U.S.–Mexican relations, symbolizing both American expansionism and Mexican vulnerability.
- It set a precedent for future U.S. territorial acquisitions and imperial ambitions in the Western Hemisphere.
- The treaty remains central to debates about national identity, citizenship, and territorial justice on both sides of the border.
