The history of the Mexican-American War is one steeped in the desire of the United States to expand and the desire of Mexico to keep what had traditionally been thought of as its territories. While there are plenty of commentaries about the Mexican-American War, the result is something that has never been questioned. The United States was able to control nearly every major battle and became richer in land because of it.
The Mexican-American War took place between 1846 and 1848. The original source of the conflict was over the territory of Texas. At one point, the Mexican government offered Americans cheap land in the territory in order to spur growth there. However, when slavery was outlawed, many of those living in Texas thought the time had come to break ties with Mexico. Texas won independence during the Texas Revolution in 1836 and eventually joined with the United States, a move that upset Mexico.
At the time, even if Mexico had agreed to recognize Texas' independence after the Texas Revolution, it still felt that having the territory become part of the United States was dangerous. Adding to the aggravation was the border of Texas and Mexico was not totally set. Some were claiming Mexico's territory ended at the Rio Grande River. Mexico claimed territory from the Nueces River south.
American troops attacked from the north under the command of Gen. Zachary Taylor and more troops under the command of Col. Stephen Kearny moved west. During initial battle at Fort Texas and Palo Alto, and at Resaca del Palma, Mexican troops suffered heavy losses. As most of the Mexican-American battles would turn out to be, these were one-sided affairs that pushed the Mexicans back past the Rio Grande. Another decisive Mexican-American battle was the Battle of Monterrey, where both sides suffered great losses, but was another setback for the Mexicans.
At the same time Mexican troops were being pressed in the North and West, another portion of the Mexican-American War was about to take place further south and east. Gen. Winfield Scott conducted an amphibious invasion near Veracruz, which pressured the Mexicans from several different fronts. After a series of battles, he eventually captured Mexico City.
This eventually led to the Treaty of Guadalupe Hidalgo. In this treaty, Mexico recognized its northern border as being the Rio Grande and gave the United States huge tracts of land in parts of what today are New Mexico, Arizona, Colorado, California, Nevada and Utah. In return for the land, the United States would pay Mexico $18.25 million US Dollars (USD). To provide some perspective, the United States had offered Mexico $25 million USD for California a year before the war broke out. This treat effectively ended the Mexican-American War.