The following examples or events are enough to prove that the Mexican-American War(1846-48)was an effort to extend American territories, and it shows the horrific imperialistic attitude of the United States. Can you provide me a response to the points brought below?

1. The philosophy of 'Manifest Destiny' was coined by John Sullivan, the editor of the Democratic Review. This term was pampered by United States as an excuse to usurp territories from its neighbours and extend its empire from Atlantic to Pacific.

2. Texas was annexed to the United States as the 28th state in spite of the opposition of Mexico

3. President Polk took office with an agenda to annex California and, even before any act of aggression, he noted the cabinet regarding the possibility of war with Mexico.

4. American invasion on the Southwest was a plan to extend slavery even to the territories of Mexico. Most of the generals who led the war were slave owners.

5. The general mood inside the country was against annexation.