The Mexican American War
1846 - 1848
A rocky start
One year prior to the start of the war, Texas was annexed by the United states into the Union. At this time, Texas composed one third of the United States' landmass. Hungry for more land, president Polk rallies for war, hoping both California and New Mexico would be taken by the United States. Texas raised other problems as well. The United States insisted that its border was at the Rio Grande river, but Mexico said it really stopped 100 miles north.
The war begins
April 25, 1964
Mexican calvary attack a group of men lead by General Zachary Taylor, killing a dozen. They then proceed to seige one of the United State's forts, formally marking the beginning of the Mexican-American War.
As you can see in the map above, the disputed land area stretches all the way to Oklahoma, a large part of the United States. While this land was not vital to the United States, the popular opinion in the south was that this was a good opportunity to spread slavery and to give the south more power in congress. Northerners of course disagreed with this view, seeing it to be an evil plot from the southern legislature. While many disagreed with each other, everyone had an opinion on what to do with Texas.
President James Polk then used the sudden act of aggression from Mexico as a reason to amplify the war, disguising it behind the need to "re-annex Texas". Polk orders the U.S. Army into the disputed area, capturing it very easily and meeting little resistance, as there were only 75,000 Mexican inhabitants. Mexico then responded by bringing back one of their most trusted generals out of exile in Cuba. Antonio López de Santa Anna is brought to Mexico, and says to president Polk that he will end the situation in the United States' favor. Instead of doing this, Lopez proceeds to double cross the United States and attacks. Luckily, the battle does not go in his favor, and Lopez retreats.
James Polk
Our eleventh president
Antonio López de Santa Anna
Mexico's president
Polk begins his master plan
Not long after the events that started the war, Polk begins his plans to invade California and New Mexico. Since the start of the war these two states have been a primary objective for him. Polk sends out Colonel Stephen Kearny to march 800 miles to Santa Fe. Unexpectedly, New Mexico falls without a single shot being fired. Colonel Kearny proceeds to march to Southern California, hoping to capture it. There they met the Republic of California, an American settler controlled group that quickly dispatched of the Mexicans in California and took it as their own. Polk had now gotten two thirds of what he had wanted, so he set his sights back on Texas.
While the Mexican generals fought gallantly, their lack of leadership marked the beginning of the end. The two major generals in charge of assaulting Mexico, Zachary Taylor and Winfield Scott, begin to make their moves. In September 1864 Taylor attacked Monterry, Mexico. Later in February 1847 Lopez ordered an attack on Zachary's troops in Buena Vista. The Mexicans had more troops, but were tired from fighting from before. Zachary's troops won, and took advantage of the situation to capture the Mexican city of Veracruz. Once again taking advantage of their situation, United States' troops took Mexico City on September 14, 1847.
Aftermath
The casualties of Mexican forces totaled over 25,000, but casualties of american forces was about 13,000. The war formally ended on February 2, 1848, just 21 months after the start. In the treaty that ended the war, the Treaty of Guadalupe Hidalgo, Mexico agreed that the United States And Mexico border was at the Rio Grande River. The United States agreed that it would pay 15 million dollars for the cession of present day California, Nevada, New Mexico, Utah, most of Arizona, and some of Colarado and Wyoming.
Sources
McDougual Little - "The Americans"
History Channel - http://www.history.com/topics/mexican-american-war
Wikipedia - http://en.m.wikipedia.org/wiki/Mexican–American_War