Causes Of The Mexican-American War

Mexican/American War 1846-1848

Between 1846-1848, two nations, the United States and Mexico went to war with each other. This was an important battle because it would transform a continent and would form new identities for all the people inhabiting the nations. The Mexican-American War was the first major conflict driven by the idea of “Manifest Destiny”; which is the belief that American had a God-given right, or destiny, to expand the country’s borders from ‘sea to shining sea.’ There were a few other driving forces for war and the outcome ended with a treaty. One cause of the war was the United States desire to expand all the way across to the Pacific Ocean. This caused conflicts with all of the U.S. neighbors such as the British in
Canada/Oregon, the Mexicans and lastly the Native Americans.

Another one of the first causes of the war was that Mexico and the United States had a struggle over who would control Texas.
American settlers began moving into Texas territory after the Revolutionary War and they started exploring the land west of the Appalachian Mountains. Once the Louisiana Purchase was passed it stretched the western boundaries of the United States more west. From gaining all of this new land Americans noticed that the Texas land was big and filled with resources but it was largely part of Mexico. In 1835, Texas declared itself independent from Mexico. Mexico was upset by this and told the Americans to leave Texas. Mexican general Antonio Lopez de Santa Anna decided that words were not enough to get his message across to America so he took action.

Mexico of course did not like the idea of its breakaway province becoming an American state. Texas, and now the United States, claimed the border at the Rio Grande River. Mexico claimed territory as far north as the Nueces River. Both nations sent troops to enforce the competing claims. On April 25, 1846, a clash occurred between Mexican and American troops on soil claimed by both countries. The war had
begun.

After the beginning of hostilities, the U.S.
military embarked on a three-pronged strategy designed to take control of northern Mexico and force an early end to the war. Two American armies moved south from Texas, while a third force under Colonel Stephen Kearny traveled west to Sante Fe, New Mexico and then to California. In a series of battles at Palo Alto and Resaca de Palma , the army of General Zachary Taylor defeated the Mexican forces and began to move south after inflicting over a thousand casualties. In July and August of 1846, the United States Navy seized Monterey and Los Angeles in California. In September, 1846, Taylor's army fought General Ampudia's forces for control of the northern Mexican city of Monterey in a bloody three-day battle. Following the capture of the city by the Americans, a temporary truce ensued which enabled both armies to recover from the exhausting Battle of Monterey. During this time, former President Santa Anna returned to Mexico from exile and raised and trained a new army of over 20,000 men to oppose the invaders. Despite the losses of huge tracts of land, and defeat in several major battles, the Mexican government refused to make peace. It became apparent to the Polk Administration that only a complete battlefield victory would end the war. Continued fighting in the dry deserts of northern Mexico convinced the United States that an overland expedition to capture of the enemy capital, Mexico City, would be hazardous and difficult. To
this end, General Winfield Scott proposed what would become the largest amphibious landing in history and a campaign to seize the capital of Mexico.

On March 9, 1847, General Scott landed with an army of 12,000 men on the beaches near Veracruz, Mexico's most important eastern port city. From this point, from March to August, Scott and Santa Anna fought a series of bloody, hard-fought battles from the coast inland toward Mexico City. The more important battles of this campaign include the Battles of Cerro Gordo Contreras, Churubusco, Molino del Rey and Chapultepec . Finally, on September 14, the American army entered Mexico City. The city's population offered some resistance to the them, but by mid-October, the disturbances had been stalled and the U.S. Army enjoyed full control. Following the city's occupation, Santa Anna resigned the presidency but retained command of his army. He attempted to continue military operations against the Americans, but his troops, beaten and disheartened, refused to fight. His government soon asked for his military resignation. Guerrilla operations continued against Scott's lines of supply back to Veracruz, but this resistance proved ineffective.

On February 2, 1848, The Treaty of Guadeloupe Hidalgo was signed, but later to be ratified by both the U.S. and Mexican Congresses. The treaty called for the annexation of the northern portions of Mexico to the United States. In return, the U.S. agreed to pay $15 million to Mexico as compensation for the seized territory. Mexican military leadership was often lacking, at least when compared to the American leadership. The war cost the United States over $100 million, and ended the lives of 13,780 U.S. military personnel. America had defeated its weaker and somewhat disorganized southern neighbor, but not without paying a terrible price.