What was the pros and cons of declaration war with Mexico?

* The United States gained a significant amount of territory, including the present-day states of California, Nevada, Utah, Arizona, New Mexico, and parts of Colorado and Wyoming.

* The victory in the war helped to boost American nationalism and pride.

* The war led to the establishment of the Rio Grande as the boundary between the United States and Mexico.

* The war increased the power and influence of the United States in the region and allowed it to become more involved in world affairs.

Cons:

* The war was a costly affair, both in terms of human life and financial resources.

* The war led to the deaths of thousands of American soldiers and Mexican civilians.

* The war caused widespread destruction in Mexico, particularly in the northern provinces.

* The war led to increased tensions between the United States and Mexico, which have persisted to this day.

* The war's legacy includes ongoing debates over the treatment of Mexican Americans in the United States.