The USA Fought Mexico and Won

As all wars, the original cause is often disputed and there are many different points of view. Some say that the war was started because of the U.S. annexation of Texas (in 1845) which Mexico continued to claim despite the fact that Texas became an independent republic 10 years prior. Others say we provoked the war by annexing Texas and deliberately placing an army at the mouth of the Rio Grande River. Yet another reason is that our president at that time (James K. Polk) forced Mexico into war in order to claim California and the southwest. A minority of people say it was because of Mexico’s failure to pay claims for losses sustained by the U.S. citizens during the Mexican war of independence. 

At the time Mexico had a really, really unstable government. The federal constitution of 1824 had been abrogated in 1835 and it was replaced by a centralized dictatorship. The government split into two factions: The centralists and the federalists.  The centralists supported an autocratic government under a ruler or dictator. The federalists supported a constitutional democracy. 

There were different clashing centralist parties that were in control of the government from 1835 to December, 1844. During this period of time, many rebellions occurred within the Mexican territory, including the temporary disaffection of California and the Texas revolution which resulted in the independence of Texas in 1836. In December, 1844, a coalition of moderates and federalists forced Mexico’s dictator; Antonio Lopez de Santa Anna,  into exile, and replaced him with Jose Joaquin Herrera as the new president of Mexico. But after the short-lived victory, the remaining centralists began plotting to overthrow Herrera.

There were still parts of the centralist government and they were prepared to declare war on the U.S. However, the Herrera government was starting to realize the independence of Texas and they were prepared to accept the loss and rest the claims question. Herrera requested that the U.S. send a minister to Mexico and Polk sent John Slidell. Slidell was authorized to purchase California and New Mexico and to settle the Texas boundary which was constantly disputed. By the time Slidell arrived in Mexico in December 1845, Things were bad. The centralists were taking down Herrera. They were appealing to the Mexican nationalist pride to try to be rid of Herrera. They were led by Mariano Parades y Arrillaya. When Slidell arrived in Mexico, Herrera refused to see him in an attempt to save Mexico. A few days later on December 14, Mariano issued a revolutionary manifesto. On January 2, 1846, Mariano entered Mexico City at the head of an army. Herrera fled and Mariano replaced him and ordered Slidell out of Mexico. Because of this. Polk ordered Zachary Taylor to position his army at the mouth of the Rio Grande. To Montario, there was no Texas boundary. To Montario, he owned Texas. Before Taylor moved into the Rio Grande, Montario already began moving troops there and he declared war on April 23, and ordered an attack on Taylor.