Pros And Cons Of The Mexican American War

American Manifest Destiny Politics in Mexican-American War

A. Overview
Mexican-American war started by the Texas annexation by the Union. Texans, who were mostly Americans, declared themselves independent in March 2, 1836 as the Republic of Texas. But they didn’t want to stand alone thus they asked to join the Union. Mexico never accepted the Republic of Texas. Thus, the areas Texas claimed, all land in the north of Rio Grande, emerged border dispute between America and Mexico.
President of United States at that time, James K. Polk, sent his army to defend Texas from Mexico invasion and suddenly conflict happened. Thus, Congress declared war in summer 1846.
This war takes one and a half year. Ended by the Treaty of Guadalupe Hidalgo
Having many settlers all over the territories supported them in gaining this. For example, by 1830 there were more than 20.000 Americans lived in Texas and they were opposing Mexicans government. “These settlers did not intend to become Mexican citizens. Instead, they planned to take over Texas.” (Out of Many, 245) Thus, it leaded to the war. Although Mexican-American war gained so many pros and contras, but it was clear that the government at that time did whatever it takes to complete their Manifest Destiny. It was the president James K.Polk from Democratic Party who was an expansionist. He was optimistic to make America stretched from the east until west coast. So, he sent his secret envoy, John Slidell to offer Mexico some money in order to buy their lands but Slidell was rejected. Angry Polk sent his army to the disputed zone making his soldiers involved in skirmish with Mexican soldiers. He lied that Mexico started it first and asked congress for war; “War exist, and, notwithstanding all our efforts to avoid it, exists by the act of Mexico herself. This claim of President Polk’s was of course contrary to fact.” (Out of Many, 247) It was clear that he wanted to expand America, although by war, because the beginning of the war was confusing, no one knows what the reality happened at the border that raised the war. Even Abraham Lincoln questioned Polk’s account of the border incident. (Out
But still, there were positive and negative impacts of this.
The most significant effect of having these new territories was economic growth in America. Not only larger lands that were considered as wealth but also the natural resources it gave. Lands and new territories might give Americans higher expectation to improve their life and find their own opportunities that lead both of the settlers and the nations’ economic welfare. But the findings of gold in California benefited a lot in the economical improvement of America. And also, the settlement and the life of its people improved significantly as clearly seen in the nearest town, San Francisco.
But apparently, there was also negative effect of gaining those new territories; there was a crash in the body of politics. There was controversy of the legalization of slavery to the new territories between the Democratic and Whigs Parties where the northern Democrats and Whigs opposed the extension of slavery while southern Democrats and Whigs supported. Ironically, it was the roots of the separation, cracked the nation into two; Union and Confederacy, and lead them to the Civil