The Mexican-American War (1846-1848) marked the first U.S. armed conflict chiefly fought on foreign soil. It pitted a politically divided and militarily unprepared Mexico against the expansionist-minded administration of U.S. President James K. Polk, who believed the United States had a “manifest destiny” to spread across the continent to the Pacific Ocean. A border skirmish along the Rio Grande started off the fighting and was followed by a series of U.S. victories. When the dust cleared, Mexico had lost about one-third of its territory, including nearly all of present-day California, Utah, Nevada, Arizona and New Mexico.Causes of the Mexican-American War
Texas gained its independence from Mexico in 1836. Initially, the United States declined to incorporate it into the union, largely because northern political interests were against the addition of a new slave state. The Mexican government was also encouraging border raids and warning that any attempt at annexation would lead to war.The Mexican-American War Begins On April 25, 1846, Mexican cavalry attacked a group of U.S. soldiers in the disputed zone under the command of General Zachary Taylor, killing about a dozen. They then laid siege to an American fort along the Rio Grande. Taylor called in reinforcements, and–with the help of superior rifles and artillery–was able to defeat the Mexicans at the battles of Palo Alto and Resaca de la Palma.Following those battles, Polk told the U.S. Congress that the “cup of forbearance has been exhausted, even before Mexico passed the boundary of the United States, invaded our territory, and shed American blood upon American soil.” Two days later, on May 13, Congress declared war, despite opposition from some northern lawmakers. No official declaration of war ever came from Mexico.Explanation: hope that helps
