The Mexican American War (1846-1848) greatly affected the United States population and demographics. This is because this war resulted in the US gaining a significant amount of territory. This included states such as California, Arizona, New Mexico, and parts of places like Utah and Colorado.
All the citizens who lived in these territories were now considered part of America. This greatly increased the overall American population. Along with this, the amount of citizens with Mexican ancestry increased greatly as well. These territories would affect the population for years to come due to the fact that gold was discovered in California. This resulted in a huge increase in the amount of Americans moving to this state.
