Why is the Mexican-American war historically important?

Answer 1

Mexican-American WarThe Mexican-American War was a war that President Polk wanted. The territory in the Southwest, after the war known as the Mexican Cession, would enable the United States to expand westward. President Polk ordered General Zachary Taylor to take 1,500 US soldiers and cross the Nueces River in Texas and proceed to the Rio Grande. Mexico considered that land as part of Mexico. Mexican troops fired on the Americans in the disputed region in April of 1846. President Polk then declared that war existed between the two nations. Actually, Congress would have to declare war, since only Congress had the constitutional power to declare war. While the war was popular in the United States, there were citizens who criticized Polk's administration for "starting" the war. A politician from Illinois by the name of Abe Lincoln voted against the war. Many in New England opposed the war because they feared the spread of slavery. Some, like Henry David Thoreau, practiced civil disobedience to protest the war.
It completed the dream of Manifest Destiny for the US.