Slavery: The Most Significant Cause Of The Mexican-American War

In 1836, Texas secured its independence from Mexico following the Battle of San Jacinto and the signing of the Treaty of Velasco. Texas became an independent country, yet almost immediately began looking to join the United States. In 1845, the U.S. annexed Texas, making it the 28th state. The causes of the Mexican-American War were slavery, and America's greed for land and manifest destiny. Although slavery was an important cause, the most significant reason was the American belief in manifest destiny to expand to California and the Pacific. Slavery was one cause of the war. In Charles Summer's speech to the state legislature of Massachusetts, he states, ¨From which slavery has already been excluded, and with the object of extending slavery and strengthening the ¨Slave Power.¨ The growth of the slaves was from a power that supported slavery. Slave power is trying to gain control of other nations to spread slavery throughout the country. If the slaves moved more to the West they would be more powerful because they have more land. Another quote that Summer stated was, ¨By a powerful nation against a weak nation.¨ This is significant because

In John O'Sullivan's article, ¨Annexation¨ he talks about manifest destiny was to spread over the continent. He makes it known that Texas is theirs by saying, ¨She is no longer to us a mere country on the map.¨ This explains that it was time for Texas to be known as something besides an alien. The painting ¨American Progress¨, by John Gast, shows an angel flying over the people leading them to the west. She is carrying light to the western frontier. In the painting, the western frontier is represented as dark and the angel is making it shine for them. She represents the freedom and enlightenment that Americans would bring to the west. This highlights why manifest destiny was the most significant reason for the Mexican-American