Why did the United States declare war against Mexico?

Question

Its a history question!!!!!! dont reply if your gonna be mean

Answer 1

They should do it again and finish the job.

Answer 2

now look at where ur feet are planted, the US soil that makes u take s**t for granted. If it wasn't for Santana just to let u know, where ur feet are planted would be Mexico

Answer 3

It had to do with what later became the state of Texas. The US had annexed Texas and Mexico refused to recognize it. The Manifest Destiny was a popular idea in the US at the time and so many people felt it was all right to go to war with a nation they knew was weaker and would lose. Mexico ended up losing a lot of land to the US, which even to this day, some Mexican-Americans use to justify allowing illegal aliens from Mexico to enter and occupy. They feel the people are taking back what's rightfully theirs.