Answer:
Step-by-step explanation:
The question of who was the aggressor in the Mexican-American War is a complex one and is open to interpretation. However, based on the historical facts presented, it can be argued that the United States was the aggressor in the war.
The United States sent troops to the Rio Grande river, which Mexico considered to be its own territory, and refused to withdraw them. This action by the United States can be seen as provocative and aggressive towards Mexico, as it involved military occupation of land that Mexico considered to be its own. Additionally, the United States had annexed Texas in 1845, which was a disputed territory between the two countries, and this had already strained relations between the two nations.
Furthermore, the fact that the United States knew that Mexico believed the boundary to be north of the Rio Grande by 100 miles, and still chose to send troops to the river, suggests that the United States was willing to use force to pursue its territorial ambitions.
Therefore, based on these historical facts, it can be argued that the United States was the aggressor in the Mexican-American War.