There were many causes of the Mexican American War. Texas Americans were angered because they did not want to follow Texas laws
President, James Polk believed in Manifest Destin., Due to this belief he was determined to secure lands from coast to coast
Many Northerners believe the annexation of Texas a was a plot to attain more slave territory. Many Americans including Abraham Lincoln believed that the US should not have used force to get Mexican lands.
The United States Army easily beat the Mexicans. The US doubled in size and became wealthy obtaining materials in new territories such as silver, copper, and wool.
80,000 Mexicans were allowed to become US citizens under the treaty of Guadalupe Hidalgo. The treaty provided protection. Mexicans were seen as equals, they were allowed the right to vote and land rights.
Because of the new territories gained from Mexico, Northerners and Southerners fought over whether the lands will become free states or slave states.