Final answer:
The Mexican-American War was caused by territorial disputes, leading to the Treaty of Guadalupe-Hidalgo, which transferred significant lands to the U.S. The Wilmot Proviso's intent to ban slavery in this new territory intensified the slavery debate, affecting both nations' political landscapes and setting the stage for the Civil War.
Step-by-step explanation:
Summary of the Mexican-American War and Related Events
The causes of the Mexican-American War were rooted in territorial disputes and the annexation of Texas. The Slidell Mission was an unsuccessful attempt by the United States to settle these disputes diplomatically by purchasing disputed territories from Mexico.
The Wilmot Proviso was a legislative proposal aimed at banning slavery in territories acquired from Mexico, sparking intense congressional debate. The conflict resulted in the Treaty of Guadalupe-Hidalgo, wherein Mexico ceded significant territories to the United States for $15 million, which eventually became states such as California, Nevada, Utah, and parts of Arizona, Colorado, and Wyoming.
Impact on the United States and Mexico
The war and subsequent treaty had a profound impact on both nations, leading to increased sectional tension in the United States over slavery and contributing to the conditions that would eventually lead to the Civil War. For Mexico, the war resulted in substantial territorial losses and fostered long-standing resentment toward the United States.
Consequences on the Territories Involved
The acquired territories experienced significant political and social upheaval, including disputes over land ownership and the disenfranchisement of the Mexican and Native American populations. The California Gold Rush and the question of admitting California as a free state expedited the resolution of the slavery debate, at least temporarily.
Political and Social Factors
Social and political factors such as the spread of "Yankeephobia" in Latin America, national debates over slavery, and sectional divides within the United States contributed to and were affected by the events of the Mexican-American War and its aftermath.