You may be wondering: What is the Mexican War and how did it begin? o What is Manifest Destiny and who invented it? These are all great questions, so let me take the time to give you some thoughts on the Mexican War and Manifest Destiny. Manifest Destiny was the belief that the United States was destined to expand from coast to coast. This was the concept that heavily influenced American politics in the 1800s. Americans supported Manifest Destiny because Southerners wanted more land and Northerners believed expansion would relieve the population. The idea was the driving force behind America's rapid expansion from the East to the West and was heavily publicized by newspapers and posters. Who invented the term Manifest Destiny? It was John L. O'Sullivan who coined the term “Manifest Destiny” to justify white settlers taking the land they coveted. It was in an article titled “Annexation,” where he first coined the term. The editorial addressed the right of the United States government regarding the annexation of Texas. Democrats took the phrase and used it in a campaign to annex many territories. John O'Sullivan wanted to use the phrase to give insight and influence to the audience. What about President James K. Polk? What was your opinion on Manifest Destiny? Well James K. Polk was a passionate expansionist who supported annexation. In Polk's inaugural address on March 4, 1845, Polk emphasized his belief in America's manifest destiny. Polk declared, “This heaven-favored land,” he proclaimed, enjoyed the “most admirable and wise system of well-regulated self-government ever devised by human minds.” Polk later moved to… midway through the document… due to war and divided families that created a political boundary along the annexed territories. The war could have been avoided and addressed differently. To conclude, the War between the United States and Mexico proved to be a violent and upsetting event for Mexican citizens that lasted from 1846 to 1848 in what is now the state of Texas. It changed the course of Mexican and American history for years to come. At the end of the war there were many misunderstandings and lack of truth. With the victory of the United States and the defeat of Mexico, Mexico lost a huge amount of land and money that was to be donated to the United States. Mexico suffered most severely during the war and at first was only trying to protect its land. The United States just wanted to expand its territory. Finally, this was the war with Mexico and how it happened with the United States.