What were the causes of the Mexican-American War?
The Mexican-American War, also known as the Mexican War, was an armed conflict between the United States and Mexico from 1846 to 1848. The main causes of the war were the annexation of Texas by the United States in 1845 and the dispute over the border between Texas and Mexico. The U.S. claimed the border was at the Rio Grande River, while Mexico claimed it was further north at the Nueces River. This territorial dispute, along with the desire for territorial expansion and Manifest Destiny, ultimately led to the outbreak of the war.
Annexation of Texas
The annexation of Texas by the United States in 1845 was a major catalyst for the Mexican-American War. Texas had declared its independence from Mexico in 1836 and sought annexation by the U.S. for several years. However, due to concerns over the balance of free and slave states in the U.S., the annexation was delayed. In 1844, James K. Polk was elected President of the U.S. with the promise of annexing Texas, and in 1845, Texas was admitted as the 28th state of the Union.
Border Dispute
The border dispute between Texas and Mexico was another significant cause of the war. Mexico did not recognize the independence of Texas and considered it a rebellious province. The U.S. claimed that the border of Texas extended to the Rio Grande River, while Mexico asserted that it was at the Nueces River. This dispute over the border region between the two rivers resulted in military conflict and skirmishes, ultimately leading to the declaration of war.
Manifest Destiny
The concept of Manifest Destiny, the belief that the U.S. was destined to expand across the North American continent, also played a role in the Mexican-American War. Many Americans believed that it was their right and duty to expand westward and spread democracy and civilization. The acquisition of new territories, such as those in present-day Texas, New Mexico, and California, was seen as fulfilling this destiny. This expansionist mindset contributed to the decision to go to war with Mexico.
The Mexican-American War had far-reaching consequences for both countries, including the cession of a vast amount of territory to the United States by Mexico through the Treaty of Guadalupe Hidalgo in 1848. Additionally, the war intensified sectional tensions in the U.S. over the issue of slavery and further solidified the concept of Manifest Destiny as a driving force behind American expansion.