The Reason for the Mexican-American War, Essay Example

The reason for the Mexican-American War had to do with land disputes.  When Texas was still a part of Mexico, it had allowed American pioneers to settle and live in Texas on official charters.  In 1835, Texas officially began a revolution to free itself from ties to Mexico.  The war lasted from October 2, 1835 to April 21, 1836. Although Texas officially won its independence from Mexico, Mexico refused to acknowledge the split and still believed it would regain control of Texas.  In 1845, Texas was annexed by the United States, which led to very bad feelings between the U.S. and Mexico.  Mexico felt as if the U.S. has stolen Texas from Mexico since they had never really acknowledged that fact that Texas was an independent country.  In addition to the situation with Texas, there was California.  The U.S. tried to buy California from Mexico on November 10, 1845 when President Polk sent John Slidell to Mexico to offer $25 million for the Mexican territories of what is today California, New Mexico, and the section of land from the Nueces to the Rio Grande rivers in Texas.  Mexico refused, due to political instability combined with national pride.  On May 13, 1846, President Polk declared war on Mexico after what is known as the Thornton Affair, when 16 U.S. Soldiers were killed by Mexican cavalry.  The men were in contested territory, the strip of land between the Rio Grande and Nueces rivers in Texas.  The United States army invaded Mexico, eventually laying siege to Mexico City.  On February 2, 1848, the Treaty of Guadalupe Hidalgo was signed, giving the United States undisputed control over Texas, making the Rio Grande the official southern most border of the state, and the states of California, Nevada, Utah, and parts of Colorado, Arizona, New Mexico and Wyoming.