Mexican-American War 1847-1848

A Proclamation by President Polk

A leaflet written by President Polk declaring that the United States should enter war with Mexico as a result of their intrusion into U.S. territories.

In March of 1845, the United States annexed Texas, a decision which caused Mexico to terminate relations with the U.S.. President Polk attempted to negotiate the terms of the new border, but Mexico refused to receive John Slidell, President Polk's representative. In May of the same year, President Polk began to consider entering war with Mexico in regards to the disputed land and in response to Mexico's refusal to negotiate. When Polk received word on April 25th that Mexican troops had crossed the Rio Grande and had killed 16 American soldiers, he made the decision to expedite the process and notify Congress as soon as possible. The President claimed Mexico "invaded our territory and shed American blood on American soil" ("Mexican"). This led to the Proclamation by President Polk, which caused the United States to enter war with Mexico. 

Battle of Buena Vista

A lithograph from 1847 depicting the Battle of Buena Vista. Created by H.R. Robinson.

Battle Scene, Battle of Buena Vista

Lithograph depicting a battle scene at the Battle of Buena Vistia, where the US Army was overwhelmingly victorious. 

The battle of Buena Vista began on February 22, 1847 in Monterrey, Mexico. The US Army, under direction of General Zachary Taylor, sent in around 5000 men to invade northeastern Mexico. On the Mexican side, General Antonio López de Santa Anna led about 14,000 troops north to confront the American invaders ("Battle of Buena Vista"). While the Mexican's had significantly more soldiers, they were severely under armed and some hardly trained, compared to a very strong and well supplied American force. General Taylor's forces were able to successfully weaken the Mexican troops causing them to retreat, marking a major success for America ("Battle of Buena Vista"). General Taylor was so successful that word of the battle helped him win the Presidency in 1849, even though he only served one year before his death. 

New Territories

The Disturnell map of 1847 was appended to the Treaty of Guadalupe Hidalgo. The map highlights the western territories, which were disputed and changed hands from Mexico to the United States. 

Treaty of Guadalupe Hidalgo

The Treaty of Guadalupe Hidalgo, which brought an official end to the Mexican-American War (1846-1848) and gained the United States substantial western territories. 

Signed on February 2, 1848, the Treaty of Guadalupe Hidalgo officially ended the Mexican-American War. The treaty was actually signed in the city of Guadalupe Hidalgo just north of the area to which the Mexican government fled to. In the treaty, Mexico ceded to the United States Upper California and New Mexico including present-day Arizona and New Mexico and parts of Utah, Nevada, and Colorado. Although Mexico ceded all of this land, the United States did pay $15,000,00 to Mexico as agreed to in the treaty (Gray). The treaty officially established the Rio Grande as the boarder between the two nations, which is still recognized today. After the war, General Zachary Taylor was so popular around the country, he became the President after Polk.

The Mexican-American war was one of the most notable events influencing Manifest Destiny. The war, while gaining extremely significant portions of land for the now United States, it set a precedent for the United States. When Mexican troops attacked the United States in the disputed territory, the US stood its ground and pushed the Mexicans back. This is important because it shows the US commitment to expansion as well as a commitment to the United States themselves. This was the first time the government ordered troops to battle on foreign soil. The war also provided the land, which would hold the gold of the California Gold Rush, arguably the most influential promotion of Manifest Destiny. 

Mexican-American War 1847-1848