Introduction

The Mexican American War was a turning point in American history and ideologically, technologically, and geographically changed America for the better. At the time it was a controversial war that fueled tensions between the North and the South even though most Americans advocated expansion. The South would support the war if the new territories would allow slavery and the North would only support the war if the territories became free states. This war would test the military strength of the United States against another organized military. In the end, America was proved victorious and its economy and territories grew with the addition of Texas, New Mexico, and the California region. The slave controversy would be temporarily put to rest when California entered as a free state. Without this war, America would have trouble becoming a global power and expanding from coast to coast.

The Mexican American War occurred from 1846 to 1848 during the U.S. presidency of President Polk and was the one of the first wars geared by the idea called “manifest destiny.” Manifest Destiny was the idea that it was America’s God-given right to bring all of North America under a civilized, Protestant, English-speaking rule. Westward migration and settling encouraged this among most Americans. America began buying land from Spain in order to achieve this goal peacefully but when Mexico, under the rule of dictator Santa Anna, refused to sell some of its territory to the United States, tensions rose between the two countries. During the Texas War of Independence, both countries claimed the region. The brutal fighting at the border made many Americans sympathize for the Texans. Texas became a U.S. state on July 4, 1845, which made the Mexicans furious. Both countries sent troops to stake their claims; Mexico saw this as an invasion of their country and the Americans viewed it as hostility towards the newly independent Texas. After a long standoff, the troops attacked each other on April 25, 1846. The Americans sought to end the war quickly by taking control of Mexican territory in California and in Northern Mexico. At first, both sides engaged in traditional European style battles using a wide range of weapons but the Mexicans soon resorted to guerilla tactics, which still proved ineffective against the superior American cannons, officers from the recently opened West Point Military Academy, and soldiers equipped with state-of-the-art rifles. The Mexicans refused to give up even after several major cities fell and only a major victory would bring peace. The Americans launched one of the largest amphibious assaults of the time period on Mexico City and successfully captured it, forcing Santa Anna to sign a treaty. Mexican president Santa Anna resigned and gave the U.S. Mexico’s northern territories and the U.S. gave them $15 million dollars in return on February 2, 1848.

Both sides had differing views on the series of events that lead to the war and each side had their heroes and famous participants in the war. The U.S. had fresh West Point graduates and soon to be Civil War heroes Ulysses S. Grant and Robert E. Lee. Zachary Taylor was also a general for the U.S. Army. The Mexican Forces were lead by Mexican President and dictator, Santa Anna who also fought against the Texans during the Texas War for Independence. The Mexican had guerilla fighters along with conventional soldiers. One of Mexico’s most powerful assets was a group of dissenting American-Catholic soldiers who joined the Mexican Army because of they did not want to fight against other Catholics. Though Mexico had a few victories and many heroic losses, America eventually won with a decisive attack on Mexico city where they decided how America Would be shaped to this day.